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The Fourteenth Amendment to the


The Fourteenth Amendment to the United States Constitution, ratified in 1868, prohibits state governments from denying citizens the “equal protection of the laws.” Although precisely what the framers of the amendment meant by this equal protection clause remains unclear, all interpreters agree that the framers’ immediate objective was to provide a constitutional warrant for the Civil Rights Act of 1866, which guaranteed the citizenship of all persons born in the United States and subject to United States jurisdiction. This declaration, which was echoed in the text of the Fourteenth Amendment, was designed primarily to counter the Supreme Court’s ruling in Dred Scott v. Sandford that Black people in the United States could be denied citizenship. The act was vetoed by President Andrew Johnson, who argued that the Thirteenth Amendment, which abolished slavery, did not provide Congress with the authority to extend citizenship and equal protection to the freed slaves. Although Congress promptly overrode Johnson’s veto, supporters of the act sought to ensure its constitutional foundations with the passage of the Fourteenth Amendment.

The broad language of the amendment strongly suggests that its framers were proposing to write into the Constitution not a laundry list (laundry list: n.细目清单) of specific civil rights but a principle of equal citizenship that forbids organized society from treating any individual as a member of an inferior class. Yet for the first eight decades of the amendment’s existence, the Supreme Court’s interpretation of the amendment betrayed this ideal of equality. In the Civil Rights Cases of 1883, for example, the Court invented the “state action” limitation, which asserts that “private” decisions by owners of public accommodations and other commercial businesses to segregate their facilities are insulated from the reach of the Fourteenth Amendment’s guarantee of equal protection under the law.

After the Second World War, a judicial climate more hospitable to equal protection claims culminated in the Supreme Court’s ruling in Brown v. Board of Education that racially segregated schools violated the equal protection clause of the Fourteenth Amendment. Two doctrines embraced by the Supreme Court during this period extended the amendment’s reach. First, the Court required especially strict scrutiny of legislation that employed a “suspect classification,” meaning discrimination against a group on grounds that could be construed as racial. This doctrine has broadened the application of the Fourteenth Amendment to other, nonracial forms of discrimination, for while some justices have refused to find any legislative classification other than race to be constitutionally disfavored, most have been receptive to arguments that at least some nonracial discriminations, sexual discrimination in particular, are “suspect” and deserve this heightened scrutiny by the courts. Second, the Court relaxed the state action limitation on the Fourteenth Amendment, bringing new forms of private conduct within the amendment’s reach.

17. Which of the following best describes the main idea of the passage?

(A) By presenting a list of specific rights, framers of the Fourteenth Amendment were attempting to provide a constitutional basis for broad judicial protection of the principle of equal citizenship.

(B) Only after the Supreme Court adopted the suspect classification approach to reviewing potentially discriminatory legislation was the applicability of the Fourteenth Amendment extended to include sexual discrimination.

(C) Not until after the Second World War did the Supreme Court begin to interpret the Fourteenth Amendment in a manner consistent with the principle of equal citizenship that it expresses.

(D) Interpreters of the Fourteenth Amendment have yet to reach consensus with regard to what its framers meant by the equal protection clause.(C)

(E) Although the reluctance of judges to extend the reach of the Fourteenth Amendment to nonracial discrimination has betrayed the principle of equal citizenship, the Supreme Court’s use of the state action limitation to insulate private activity from the amendment’s reach has been more harmful.

18. The passage suggests that the principal effect of the state action limitation was to

(A) allow some discriminatory practices to continue unimpeded by the Fourteenth Amendment

(B) influence the Supreme Court’s ruling in Brown v, Board of Education

(C) provide expanded guidelines describing prohibited actions

(D) prohibit states from enacting laws that violated the intent of the Civil Rights Act of 1866(A)

(E) shift to state governments the responsibility for enforcement of laws prohibiting discriminatory practices

19. The author’s position regarding the intent of the framers of the Fourteenth Amendment would be most seriously undermined if which of the following were true?

(A) The framers had anticipated state action limitations as they are described in the passage.

(B) The framers had merely sought to prevent discriminatory acts by federal officials.

(C) The framers were concerned that the Civil Rights Act of 1866 would be overturned by the Supreme Court.

(D) The framers were aware that the phrase “equal protection of the laws” had broad implications.(B)

(E) The framers believed that racial as well as non-racial forms of discrimination were unacceptable.

20. According to the passage, the original proponents of the Fourteenth Amendment were primarily concerned with

(A) detailing the rights afforded by the principle of equal citizenship

(B) providing support in the Constitution for equal protection for all citizens of the United States

(C) closing a loophole that could be used to deny individuals the right to sue for enforcement of their civil rights

(D) asserting that the civil rights protected by the Constitution included nonracial discrimination as well as racial discrimination(B)

(E) granting state governments broader discretion in interpreting the Civil Rights Act of 1866

21. The author implies that the Fourteenth Amendment might not have been enacted if

(A) Congress’ authority with regard to legislating civil rights had not been challenged

(B) the framers had anticipated the Supreme Court’s ruling in Brown v. Board of Education

(C) the framers had believed that it would be used in deciding cases of discrimination involving non-racial groups

(D) most state governments had been willing to protect citizens’ civil rights(A)

(E) its essential elements had not been implicit in the Thirteenth Amendment

22. According to the passage, which of the following most accurately indicates the sequence of the events listed below?

I. Civil Rights Act of 1866

II. Dred Scott v. Sandford

III. Fourteenth Amendment

IV. Veto by President Johnson

(A) I, II, III, IV

(B) I, IV, II, III

(C) I, IV, III, II

(D) II, I, IV, III(D)

(E) III, II, I, IV

23. Which of the following can be inferred about the second of the two doctrines referred to in lines 39-41 of the passage?

(A) It caused some justices to rule that all types of discrimination are prohibited by the Constitution.

(B) It shifted the focus of the Supreme Court from racial to nonracial discrimination.

(C) It narrowed the concern of the Supreme Court to legislation that employed a suspect classification.

(D) It caused legislators who were writing new legislation to reject language that could be construed as permitting racial discrimination.(E)

(E) It made it more difficult for commercial businesses to practice racial discrimination.


  1. By 1950, the results of attempts


By 1950, the results of attempts to relate brain processes to mental experience appeared rather discouraging. Such variations in size, shape, chemistry, conduction speed, excitation threshold, and the like as had been demonstrated in nerve cells remained negligible in significance for any possible correlation with the manifold dimensions of mental experience.

Near the turn of the century, it had been suggested by Hering that different modes of sensation, such as pain, taste, and color, might be correlated with the discharge of specific kinds of nervous energy. However, subsequently developed methods of recording and analyzing nerve potentials failed to reveal any such qualitative diversity. It was possible to demonstrate by other methods refined structural differences among neuron types; however, proof was lacking that the quality of the impulse or its condition was influenced by these differences, which seemed instead to influence the developmental patterning of the neural circuits. Although qualitative variance among nerve energies was never rigidly disproved, the doctrine was generally abandoned in favor of the opposing view, namely, that nerve impulses are essentially homogeneous in quality and are transmitted as “common currency” throughout the nervous system. According to this theory, it is not the quality of the sensory nerve (sensory nerve: 感觉神经) impulses that determines the diverse conscious sensations they produce, but rather the different areas of the brain into which they discharge, and there is some evidence for this view. In one experiment, when an electric stimulus was applied to a given sensory field of the cerebral cortex of a conscious human subject, it produced a sensation of the appropriate modality (modality: n.形式, 形态, 特征) for that particular locus, that is, a visual sensation from the visual cortex, an auditory sensation from the auditory cortex, and so on. Other experiments revealed slight variations in the size, number, arrangement, and interconnection of the nerve cells, but as far as psychoneural correlations were concerned, the obvious similarities of these sensory fields to each other seemed much more remarkable than any of the minute differences.

However, cortical locus, in itself, turned out to have little explanatory value. Studies showed that sensations as diverse as those of red, black, green, and white, or touch, cold, warmth, movement, pain, posture, and pressure apparently may arise through activation of the same cortical areas. What seemed to remain was some kind of differential patterning effects in the brain excitation: it is the difference in the central distribution of impulses that counts. In short, brain theory suggested a correlation between mental experience and the activity of relatively homogeneous nerve-cell units conducting essentially homogeneous impulses through homogeneous cerebral tissue. To match the multiple dimensions of mental experience psychologists could only point to a limitless variation in the spatiotemporal patterning of nerve impulses.

21. The author suggests that, by 1950, attempts to correlate mental experience with brain processes would probably have been viewed with

(A) indignation

(B) impatience

(C) pessimism

(D) indifference(C)

(E) defiance

22. The author mentions “common currency” in line 26 primarily in order to emphasize the

(A) lack of differentiation among nerve impulses in human beings

(B) similarity of the sensations that all human beings experience

(C) similarities in the views of scientists who have studied the human nervous system

(D) continuous passage of nerve impulses through the nervous system(A)

(E) recurrent questioning by scientists of an accepted explanation about the nervous system

23. The description in lines 32-38 of an experiment in which electric stimuli were applied to different sensory fields of the cerebral cortex tends to support the theory that

(A) the simple presence of different cortical areas cannot account for the diversity of mental experience

(B) variation in spatiotemporal patterning of nerve impulses correlates with variation in subjective experience

(C) nerve impulses are essentially homogeneous and are relatively unaffected as they travel through the nervous system

(D) the mental experiences produced by sensory nerve impulses are determined by the cortical area activated(D)

(E) variation in neuron types affects the quality of nerve impulses

24. According to the passage, some evidence exists that the area of the cortex activated by a sensory stimulus determines which of the following?

I. The nature of the nerve impulse

II. The modality of the sensory experience

III. Qualitative differences within a modality

(A) II only

(B) III only

(C) I and II only

(D) II and III only(A)

(E) I, II and III

25. The passage can most accurately be described as a discussion concerning historical views of the

(A) anatomy of the brain

(B) manner in which nerve impulses are conducted

(C) significance of different cortical areas in mental experience

(D) mechanics of sense perception(E)

(E) physiological correlates of mental experience

26. Which of the following best summarizes the author’s opinion of the suggestion that different areas of the brain determine perceptions produced by sensory nerve impulses?

(A) It is a plausible explanation, but it has not been completely proved.

(B) It is the best explanation of brain processes currently available.

(C) It is disproved by the fact that the various areas of the brain are physiologically very similar.

(D) There is some evidence to support it, but it fails to explain the diversity of mental experience.(D)

(E) There is experimental evidence that confirms its correctness.

27. It can be inferred from the passage that which of the following exhibit the LEAST qualitative variation?

(A) Nerve cells

(B) Nerve impulses

(C) Cortical areas

(D) Spatial patterns of nerve impulses(B)

(E) Temporal patterns of nerve impulses




  1. Biologists have long maintained


Biologists have long maintained that two groups of pinnipeds (pinniped: adj.鳍足类的), sea lions and walruses, are descended from a terrestrial bearlike animal, whereas the remaining group, seals, shares an ancestor with weasels. But the recent discovery of detailed similarities in the skeletal structure of the flippers in all three groups undermines the attempt to explain away (1: to get rid of by or as if by explanation; 2: to minimize the significance of by or as if by explanation) superficial resemblance as due to convergent evolution (convergent evolution: 趋同进化)—the independent development of similarities between unrelated groups in response to similar environmental pressures. Flippers may indeed be a necessary response to aquatic life; turtles, whales, and dugongs (an aquatic herbivorous mammal of a monotypic genus (Dugong) that has a bilobed tail and in the male upper incisors altered into short tusks, is related to the manatee, and inhabits warm coastal regions) also have them. But the common detailed design found among the pinnipeds probably indicates a common ancestor. Moreover, walruses and seals drive themselves through the water with thrusts of their hind flippers, but sea lions use their front flippers. If anatomical similarity in the flippers resulted from similar environmental pressures, as posited by the convergent evolution theory, one would expect walruses and seals, but not seals and sea lions, to have similar flippers.

24. According to the passage, it has been recently discovered that

(A) there are detailed skeletal similarities in the flippers of pinnipeds

(B) sea lions, seals, and walruses are all pinnipeds

(C) pinnipeds are descended from animals that once lived on land

(D) animals without common ancestors sometimes evolve in similar ways(A)

(E) animals that have flippers do not all use them in the same way

25. The author implies that which of the following was part of the long-standing view concerning pinnipeds?

(A) Pinnipeds are all descended from a terrestrial bearlike animal.

(B) Pinnipeds share a common ancestor with turtles, whales, and dugongs.

(C) Similarities among pinnipeds are due to their all having had to adapt to aquatic life.

(D) There are detailed similarities in the skeletal structure of the flippers in all pinnipeds.(C)

(E) Convergent evolution cannot account for the similarities among pinnipeds.

26. The author implies which of the following about the fact that turtles, whales, and dugongs all have flippers?

(A) It can be explained by the hypothesis that turtles, whales, and dugongs are very closely related.

(B) It can be explained by the idea of convergent evolution.

(C) It suggests that turtles, whales, and dugongs evolved in separate parts of the world.

(D) It undermines the view that turtles, whales, and dugongs are all descended from terrestrial ancestors.(B)

(E) It is the primary difference between turtles, whales, and dugongs, on the one hand, and pinnipeds, on the other.

27. In presenting the argument in the passage, the author does which of the following?

(A) Contends that key terms in an opposing view have been improperly used.

(B) Contends that opponents have purposely obscured important evidence.

(C) Shows that two theories thought to be in conflict are actually complementary.

(D) Shows that advocates of a theory have not always stated their view in the same manner.(E)

(E) Shows that an implication of a theory is contradicted by the facts.


  1. The more that is discovered about the


The more that is discovered about the intricate organization of the nervous system, the more it seems remarkable that genes can successfully specify the development of that system. Human genes contain too little information even to specify which hemisphere of the brain each of a human’s 1011 neurons should occupy, let alone the hundreds of connections that each neuron makes. For such reasons, we can assume that there must be an important random factor in neural development, and in particular, that errors must and do occur in the development of all normal brains.

The most vivid expression of such errors occurs in genetically identical (isogenic) organisms. Even when reared under the same conditions, isogenic organisms are rarely exact copies of one another, and their differences have revealed much about the random variations that result from (result from: v.由...产生) an organism’s limited supply of genetic information. In isogenic Daphniae, for example, even though the position, size, and branching pattern of each optic neuron are remarkably constant, there is some variability in connectivity, and the number of synapses varies greatly. This variability is probably the result of random scatter beyond the resolution of genetic control and is best termed “imprecision,” since its converse, the degree of clustering about a mean, is conventionally, called “precision.”

Imprecision should be distinguished from developmental mistakes: wrongly migrated neurons, incorrect connections, and the like. To use a computer analogy, minor rounding-off errors occur universally and are analogous to imprecision, but occasionally a binary digit is incorrectly transmitted, perhaps ruining a calculation, and this incorrect transmission is analogous to a developmental mistake. Thus, imprecision is a form of inaccuracy inherent within the limits of design, but mistakes are forms of gross fallibility.

Both imprecision and gross fallibility can plausibly be blamed on the insufficiency of genetic information, since either could be reduced by adding more information. It is universally accepted among information theorists that codes and languages can be made mistake-resistant by incorporating redundancy. However, since the amount of space available in any information system is limited, increased redundancy results in decreased precision. For example, π when written incorrectly in English, “three point oen four two, “can be understood correctly even though a typographical error has occurred. More precision could be gained, however, if those 24 spaces were filled with Arabic numerals (Arabic numerals: n.阿拉伯数字); then π could be expressed to 23 significant digits (one of the digits of a number beginning with the digit farthest to the left that is not zero and ending with the last digit farthest to the right that is not zero or is a zero considered to be exact called also significant figure), although any error would significantly change the meaning. There exists a trade-off (a giving up of one thing in return for another: EXCHANGE), the more precisely a system is specified, using a given limited amount of information, the greater the danger of gross mistakes. The overall scheme by which genetic information is rationed out (ration out: adv.应按配额给定地) in organisms, therefore, must involve a compromise between two conflicting priorities: precision and the avoidance of gross mistakes.

17. Which of the following best expresses the main idea of the passage?

(A) Although studies of isogenic organisms have shown that all organisms are subject to developmental variations, there is still scientific debate over the exact causes of these variations.

(B) Because of limitations on the amount of information contained in the genes of organisms, developing nervous systems are subject to two basic kinds of error, the likelihood of one of which is reduced only when the likelihood of the other is increased.

(C) The complexity of an organism’s genetic information means that much of the unusual variation that occurs among organisms can best be explained as the result of developmental mistakes.

(D) New findings about the nature of the genetic control of neural development support the work of some scientists who argue that the computer is an extremely useful model for understanding the nervous system.(B)

(E) The major discovery made by scientists studying the genetic control of neural development is that both imprecision and gross developmental error can be traced to specific types of mutations in specific genes.

18. According to the passage, one of the reasons it has been assumed that there is an important random element in human neural development is that

(A) genes cannot specify certain types of developmental processes as well as they can others

(B) the intricacy of the nervous system allows small developmental errors to occur without harmful effects

(C) the amount of information contained in the genes is less than the amount necessary to specify the location of the neurons

(D) the number of neurons in the human brain varies greatly from individual to individual(C)

(E) it is theoretically impossible for an organism to protect itself completely from gross developmental mistakes

19. The author suggests which of the following about the findings of information theorists?

(A) Their findings provocatively challenge the standard explanation of redundancy in genes.

(B) Their findings provide useful insights into understanding the rationing of genetic information.

(C) Their findings help to explain why imprecision can occur in neural development but not why gross mistakes can occur.

(D) Their findings suggest that genes may be able to specify neural development more accurately than had previously been thought.(B)

(E) Their findings support the work of those who use computer operations as models for understanding genetic control.

20. According to the passage, of the following aspects of the optic neurons of isogenic Daphniae, which varies the most?

(A) Size


(B) Connectivity

(C) Position

(D) Branching pattern(E)

(E) Number of synapses

21. Which of the following best describes the organization of the first paragraph?

(A) A specific case is presented, its details are analyzed, and a conclusion is drawn from it.

(B) A discovery is announced, its most significant application is discussed, and possibilities for the future are suggested.

(C) A generalization is made, specific situations in which it is applicable are noted, and problems with it are suggested.

(D) An observation is made, specifics are provided to support it, and a generalization is derived.(D)

(E) A hypothesis is presented, its implications are clarified, and applications of it are discussed.

22. The author uses all of the following to clarify the distinction between imprecision and gross mistake in neural development EXCEPT

(A) classification of borderline phenomena

(B) a description of the relationship between the phenomena denoted by each term

(C) specific examples of the phenomena denoted by each term

(D) an explanation of at least one of the key terms involved(A)

(E) analogies to other types of phenomena

23. Which of the following can be inferred from the passage about the genetic information of Daphniae?

I. There is probably some degree of redundancy in the information controlling neural development.

II. Most of the information for neural development stored in the genes is used to specify the positions of the optic neurons.

III. There is sufficient information to preclude the occurrence of gross mistakes during neural development.

(A) I only

(B) II only

(C) III only

(D) I and II only(A)

(E) II and III only


  1. What causes a helix in nature to


What causes a helix in nature to appear with either a dextral (“right-handed,” or clockwise) twist or a sinistral (“left-handed,” or counterclockwise) twist is one of the most intriguing puzzles in the science of form. Most spiral-shaped snail species are predominantly dextral. But at one time (at one time: adv.同时, 曾经), handedness (twist direction of the shell) was equally distributed within some snail species that have become predominantly dextral or, in a few species, predominantly sinistral. What mechanisms, control handedness and keep left-handedness rare?

It would seem unlikely that evolution should discriminate against (discriminate against: v.歧视) sinistral snails if sinistral and dextral snails are exact mirror images, for any disadvantage that a sinistral twist in itself could confer on its possessor is almost inconceivable. But left- and right-handed snails are not actually true mirror images of one another. Their shapes are noticeably different. Sinistral rarity might, then, be a consequence of possible disadvantages conferred by these other concomitant structural features. In addition, perhaps left- and right-handed snails cannot mate with each other, having incompatible twist directions. Presumably an individual of the rarer form would have relative difficulty in finding a mate of the same hand, thus keeping the rare form rare or creating geographically separated right-and left-handed populations.

But this evolutionary mechanism combining dissymmetry, anatomy, and chance does not provide an adequate explanation of why right-handedness should have become predominant. It does not explain, for example, why the infrequent unions between snails of opposing hands produce fewer offspring of the rarer than the commoner form in species where each parent contributes equally to handedness. Nor does it explain why, in a species where one parent determines handedness, a brood is not exclusively right- or left-handed when the offspring would have the same genetic predisposition. In the European pond snail Lymnaea peregra, a predominantly dextral species whose handedness is maternally determined, a brood might be expected to be exclusively right or left-handed—and this often occurs. However, some broods possess a few snails of the opposing hand, and in predominantly sinistral broods, the incidence of dextrality is surprisingly high.

Here, the evolutionary theory must defer to a theory based on an explicit developmental mechanism that can favor either right or left-handedness. In the case of (in the case of: adv.在...的情况) Lymnaea peregra, studies indicate that a dextral gene is expressed during egg formation; i.e., before egg fertilization, the gene produces a protein, found in the cytoplasm of the egg, that controls the pattern of cell division (cell division: n.细胞分裂) and thus handedness. In experiments, an injection of cytoplasm from dextral eggs changes the pattern of sinistral eggs, but an injection from sinistral eggs does not influence dextral eggs. One explanation for the differing effects is that all Lymnaea peregra eggs begin left-handed but most switch to being right-handed. Thus, the path to a solution to the puzzle of handedness in all snails appears to be as twisted as the helix itself.

21. Which of the following would serve as an example of “concomitant structural features” (line 19) that might disadvantage a snail of the rarer form?

(A) A shell and body that are an exact mirror image of a snail of the commoner form

(B) A smaller population of the snails of the rarer form

(C) A chip or fracture in the shell caused by an object falling on it

(D) A pattern on the shell that better camouflages it(E)

(E) A smaller shell opening that restricts mobility and ingestion relative to that of a snail of the commoner form

22. The second paragraph of the passage is primarily concerned with offering possible reasons why

(A) it is unlikely that evolutionary mechanisms could discriminate against sinistral snails

(B) sinistrality is relatively uncommon among snail species

(C) dextral and sinistral populations of a snail species tend to intermingle

(D) a theory based on a developmental mechanism inadequately accounts for the predominance of dextrality across snail species(B)

(E) dextral snails breed more readily than sinistral snails, even within predominantly sinistral populations

23. In describing the “evolutionary mechanism” (line 27), the author mentions which of the following?

(A) The favorable conditions for nurturing new offspring

(B) The variable environmental conditions that affect survival of adult snails

(C) The availability of potential mates for breeding

(D) The structural identity of offspring to parents of the same hand(C)

(E) The frequency of unions between snails of different species

24. According to the passage, which of the following is true of Lymnaea peregra?

(A) Handedness within the species was at one time equally distributed between left and right.

(B) Under laboratory conditions, dextral eggs from Lymnaea peregra can be artificially induced to develop into sinistral snails.

(C) Broods of Lymnaea peregra are, without variation, exclusively sinistral or dextral.

(D) Handedness in Lymnaea peregra offspring is determined by only one of the parents.(D)

(E) Geographic factors have played a larger role than has genetics in the evolution of the species.

25. The passage implies that in Lymnaea peregra, there will generally be

(A) more offspring of the nondominant hand in broods where handedness is determined after, rather than before, fertilization

(B) a sinistral gene that produces a protein in the cytoplasm of the egg cell

(C) fewer sinistral offspring in dextral broods than dextral offspring in sinistral broods

(D) equal numbers of exclusively left-and right-handed broods(C)

(E) an increasing occurrence of left-handedness in successive broods

26. It can be inferred from the passage that a predominantly sinistral snail species might stay predominantly sinistral for each of the following reasons EXCEPT for

(A) a developmental mechanism that affects the cell-division pattern of snails

(B) structural features that advantage dextral snails of the species

(C) a relatively small number of snails of the same hand for dextral snails of the species to mate with

(D) anatomical incompatibility that prevents mating between snails of opposing hands within the species(B)

(E) geographic separation of sinistral and dextral populations

27. Which of the following accurately describes the relationship between the evolutionary and developmental theories discussed in the passage?

(A) Although the two theories reach the same conclusion, each is based on different assumptions.

(B) They present contradictory explanations of the same phenomenon.

(C) The second theory accounts for certain phenomena that the first cannot explain.

(D) The second theory demonstrates why the first is valid only for very unusual, special cases.(C)

(E) They are identical and interchangeable in that the second theory merely restates the first in less technical terms.




  1. The defoliation of millions of acres


The defoliation of millions of acres of trees by massive infestations of gypsy moth (gypsy moth: 舞毒蛾) caterpillars is a recurring phenomenon in the northeastern United States. In studying these outbreaks, scientists have discovered that affected trees fight back by releasing toxic chemicals, mainly phenols, into their foliage. These noxious substances limit caterpillars’ growth and reduce the number of eggs that female moths lay. Phenols also make the eggs smaller, which reduces the growth of the following year’s caterpillars. Because the number of eggs a female moth produces is directly related to her size, and because her size is determined entirely by her feeding success as a caterpillar, the trees’ defensive mechanism has an impact on moth fecundity.

The gypsy moth is also subject to attack by the nucleopolyhedrosis virus, or wilt disease (wilt disease: 落叶病), a particularly important killer of the caterpillars in outbreak years. Caterpillars contract wilt disease when they eat a leaf to which the virus, encased in a protein globule, has become attached. Once ingested by a caterpillar, the protein globule dissolves, releasing thousands of viruses, or virions, that after about two weeks multiply enough to fill the entire body cavity. When the caterpillar dies, the virions are released to the outside, encased in a new protein globule synthesized from the caterpillar’s tissues and ready to be picked up by other caterpillars.

Knowing that phenols, including tannins, often act by associating with and altering the activity of proteins, researchers focused on the effects on caterpillars of ingesting the virus and leaves together. They found that on tannin-rich oak leaves, the virus is considerably less effective at killing caterpillars than when it is on aspen leaves, which are lower in phenols. In general, the more concentrated the phenols in tree leaves, the less deadly the virus. Thus, while highly concentrated phenols in tree leaves reduce the caterpillar population by limiting the size of caterpillars and, consequently, the size of the female’s egg cluster, these same chemicals also help caterpillars survive by disabling the wilt virus. Forest stands of red oaks, with their tannin-rich foliage, may even provide caterpillars with safe havens from disease. In stands dominated by trees such as aspen, however, incipient gypsy moth outbreaks are quickly suppressed by viral epidemics.

Further research has shown that caterpillars become virtually immune to the wilt virus as the trees on which they feed respond to increasing defoliation. The trees’ own defenses raise the threshold of caterpillar vulnerability to the disease, allowing populations to grow denser without becoming more susceptible to infection. For these reasons, the benefits to the caterpillars of ingesting phenols appear to outweigh the costs. Given the presence of the virus, the trees’ defensive tactic apparently has backfired (backfire: to have the reverse of the desired or expected effect).

17. Which of the following statements best expresses the main point of the passage?

(A) Recurring outbreaks of infestation by gypsy moth caterpillars have had a devastating impact on trees in the northeastern United States.

(B) A mechanism used by trees to combat the threat from gypsy moth caterpillars has actually made some trees more vulnerable to that threat.

(C) Although deadly to gypsy moth caterpillars, wilt disease has failed to significantly affect the population density of the caterpillars.

(D) The tree species with the highest levels of phenols in their foliage are the most successful in defending themselves against gypsy moth caterpillars.(B)

(E) In their efforts to develop new methods for controlling gypsy moth caterpillars, researchers have focused on the effects of phenols in tree leaves on the insects’ growth and reproduction.

18. In lines 12-14, the phrase “the trees’ defensive mechanism has an impact on moth fecundity” refers to which of the following phenomena?

(A) Female moths that ingest phenols are more susceptible to wilt virus, which causes them to lay smaller eggs.

(B) Highly concentrated phenols in tree leaves limit caterpillars’ food supply, thereby reducing the gypsy moth population.

(C) Phenols attack the protein globule that protects moth egg clusters, making them vulnerable to wilt virus and lowering their survival rate.

(D) Phenols in oak leaves drive gypsy moths into forest stands dominated by aspens, where they succumb to viral epidemics.(E)

(E) The consumption of phenols by caterpillars results in undersized female gypsy moths, which tend to produce small egg clusters.

19. It can be inferred from the passage that wilt disease virions depend for their survival on

(A) protein synthesized from the tissues of a host caterpillar

(B) aspen leaves with high concentrations of phenols

(C) tannin-rich oak leaves

(D) nutrients that they synthesize from gypsy moth egg clusters(A)

(E) a rising threshold of caterpillar vulnerability to wilt disease

20. Which of the following, if true, would most clearly demonstrate the operation of the trees’ defensive mechanism as it is described in the first paragraph of the passage?

(A) Caterpillars feeding on red oaks that were more than 50 percent defoliated grew to be only two-thirds the size of those feeding on trees with relatively intact foliage.

(B) Oak leaves in areas unaffected by gypsy moths were found to have higher levels of tannin on average than aspen leaves in areas infested with gypsy moths.

(C) The survival rate of gypsy moth caterpillars exposed to the wilt virus was 40 percent higher for those that fed on aspen leaves than for those that ate oak leaves.

(D) Female gypsy moths produced an average of 25 percent fewer eggs in areas where the wilt virus flourished than did moths in areas that were free of the virus.(A)

(E) Gypsy moth egg clusters deposited on oak trees were found to have relatively large individual eggs compared to those deposited on aspen trees.

21. Which of the following best describes the function of the third paragraph of the passage?

(A) It resolves a contradiction between the ideas presented in the first and second paragraphs.

(B) It introduces research data to support the theory outlined in the second paragraph.

(C) It draws a conclusion from conflicting evidence presented in the first two paragraphs.

(D) It shows how phenomena described in the first and second paragraphs act in combination.(D)

(E) It elaborates on the thesis introduced in the first paragraph after a digression in the second paragraph.

22. It can be inferred from the passage that gypsy moth caterpillars become immune to the wilt virus as a result of

(A) consuming a wide range of nutrients from a variety of leaf types

(B) feeding on leaves that contain high levels of phenols

(C) producing fewer offspring, which favors the survival of the hardiest individuals

(D) ingesting the virus together with leaves that do not contain tannin(B)

(E) growing population density, which outstrips the ability of the virus to multiply and spread

23. Which of the following statements about gypsy moth caterpillars is supported by information presented in the passage?

(A) Wilt disease is more likely to strike small gypsy moth caterpillars than large ones.

(B) The concentration of phenols in tree leaves increases as the gypsy moth caterpillar population dies off.

(C) Female gypsy moth caterpillars stop growing after they ingest leaves containing phenols.

(D) Differing concentrations of phenols in leaves have differing effects on the ability of the wilt virus to kill gypsy moth caterpillars.(D)

(E) The longer a gypsy moth population is exposed to wilt disease, the greater the likelihood that the gypsy moth caterpillars will become immune to the virus.




  1. The recent, apparently successful,


The recent, apparently successful, prediction by mathematical models of an appearance of El Nino—the warm ocean current that periodically develops along the Pacific coast of South America—has excited researchers. Jacob Bjerknes pointed out over 20 years ago how winds might create either abnormally warm or abnormally cold water in the eastern equatorial Pacific. Nonetheless, until the development of the models no one could explain why conditions should regularly shift from one to the other, as happens in the periodic oscillations between appearances of the warm El Nino and the cold so-called anti-El Nino. The answer, at least if the current model that links the behavior of the ocean to that of the atmosphere is correct, is to be found in the ocean.

It has long been known that during an El Nino, two conditions exist: (1) unusually warm water extends along the eastern Pacific, principally along the coasts of Ecuador and Peru, and (2) winds blow from the west into the warmer air rising over the warm water in the east. These winds tend to create a feedback mechanism (feedback mechanism: 反馈机制) by driving the warmer surface water into a “pile” that blocks the normal upwelling (upwelling: n.上涌;上升流(指海水由较深层上升到较浅层的过程)) of deeper, cold water in the east and further warms the eastern water, thus strengthening the wind still more. The contribution of the model is to show that the winds of an El Nino, which raise sea level in the east, simultaneously send a signal to the west lowering sea level. According to the model, that signal is generated as a negative Rossby wave, a wave of depressed, or negative, sea level, that moves westward parallel to the equator at 25 to 85 kilometers per day. Taking months to traverse the Pacific, Rossby waves march to the western boundary of the Pacific basin, which is modeled as a smooth wall but in reality consists of quite irregular island chains, such as the Philippines and Indonesia.

When the waves meet the western boundary, they are reflected, and the model predicts that Rossby waves will be broken into numerous coastal Kelvin waves carrying the same negative sea-level signal. These eventually shoot toward the equator, and then head eastward along the equator propelled by the rotation of the Earth at a speed of about 250 kilometers per day. When enough Kelvin waves of sufficient amplitude arrive from the western Pacific, their negative sea-level signal overcomes the feedback mechanism tending to raise the sea level, and they begin to drive the system into the opposite cold mode. This produces a gradual shift in winds, one that will eventually send positive sea-level Rossby waves westward, waves that will eventually return as cold cycle-ending positive Kelvin waves, beginning another warming cycle.

21. The primary function of the passage as a whole is to

(A) introduce a new explanation of a physical phenomenon

(B) explain the difference between two related physical phenomena

(C) illustrate the limitations of applying mathematics to complicated physical phenomena

(D) indicate the direction that research into a particular physical phenomenon should take(A)

(E) clarify the differences between an old explanation of a physical phenomenon and a new model of it

22. Which of the following best describes the organization of the first paragraph?

(A) A theory is presented and criticized.

(B) A model is described and evaluated.

(C) A result is reported and its importance explained.

(D) A phenomenon is noted and its significance debated.(C)

(E) A hypothesis is introduced and contrary evidence presented.

23. According to the passage, which of the following features is characteristic of an El Nino?

(A) Cold coastal water near Peru

(B) Winds blowing from the west

(C) Random occurrence

(D) Worldwide effects(B)

(E) Short duration

24. According to the model presented in the passage, which of the following normally signals the disappearance of an El Nino?

(A) The arrival in the eastern Pacific of negative sea-level Kelvin waves.

(B) A shift in the direction of the winds produced by the start of an anti-El Nino elsewhere in the Pacific.

(C) The reflection of Kelvin waves after they reach the eastern boundary of the Pacific, along Ecuador and Peru.

(D) An increase in the speed at which negative Rossby waves cross the Pacific.(A)

(E) The creation of a reservoir of colder, deep ocean water trapped under the pile of warmer, surface ocean water.

25. It can be inferred from the passage that which of the following would result fairly immediately from the cessation of the winds of an El Nino?

I. Negative Rossby waves would cease to be generated in the eastern Pacific.

II. The sea level in the eastern Pacific would fall.

III. The surface water in the eastern Pacific would again be cooled by being mixed with deep water.

(A) I only

(B) II only

(C) I and II only

(D) I and III only(E)

(E) I, II, and III

26. Which of the following, if true, would most seriously undermine the validity of the model of El Nino that is presented in the passage?

(A) During some years El Nino extends significantly farther along the coasts of Ecuador and Peru than during other years.

(B) During periods of unusually cool temperatures along the eastern Pacific, an El Nino is much colder than normal.

(C) The normal upwelling of cold water in the eastern Pacific depends much more on the local characteristics of the ocean than on atmospheric conditions.

(D) The variations in the time it takes Rossby waves to cross the Pacific depend on the power of the winds that the waves encounter.(E)

(E) The western boundary of the Pacific basin is so irregular that it impedes most coastal Kelvin waves from heading eastward.

27. The passage best supports the conclusion that during an anti-El Nino the fastest-moving signal waves are

(A) negative Rossby waves moving east along the equator

(B) positive Rossby waves moving west along the equator

(C) negative Kelvin waves moving west along the equator

(D) positive Kelvin waves moving west along the equator(E)

(E) positive Kelvin waves moving east along the equator




  1. The term “remote sensing (remote sensing: 遥感, 遥测, 远距离读出)” refers


The term “remote sensing (remote sensing: 遥感, 遥测, 远距离读出)” refers to the techniques of measurement and interpretation of phenomena from a distance. Prior to the mid-1960’s the interpretation of film images was the primary means for remote sensing of the Earth’s geologic features. With the development of the optomechanical scanner, scientists began to construct digital multispectral images using data beyond the sensitivity range of visible light photography. These images are constructed by mechanically aligning pictorial representations of such phenomena as the reflection of light waves outside the visible spectrum, the refraction of radio waves, and the daily changes in temperature in areas on the Earth’s surface. Digital multispectral imaging has now become the basic tool in geologic remote sensing from satellites.

The advantage of digital over photographic imaging is evident: the resulting numerical data are precisely known, and digital data are not subject to the vagaries of difficult-to-control chemical processing. With digital processing, it is possible to combine a large number of spectral images. The acquisition of the first multispectral digital data set from the multispectral scanner (MSS) aboard the satellite Landsat (landsat: n.(美国)地球资源(探测)卫星) in 1972 consequently attracted the attention of the entire geologic community. Landsat MSS data are now being applied to a variety of geologic problems that are difficult to solve by conventional methods alone. These include specific problems in mineral and energy resource exploration and the charting of glaciers and shallow seas.

A more fundamental application of remote sensing is to augment conventional methods for geologic mapping of large areas. Regional maps present compositional, structural, and chronological information for reconstructing geologic evolution. Such reconstructions have important practical applications because the conditions under which rock units and other structural features are formed influence the occurrence of ore and petroleum deposits and affect the thickness and integrity of the geologic media in which the deposits are found.

Geologic maps incorporate a large, varied body of specific field and laboratory measurements, but the maps must be interpretative because field measurements are always limited by rock exposure, accessibility and labor resources. With remote-sensing techniques it is possible to obtain much geologic information more efficiently than it can be obtained on the ground. These techniques also facilitate overall interpretation. Since detailed geologic mapping is generally conducted in small areas, the continuity of regional features that have intermittent and variable expressions is often not recognized, but in the comprehensive views of Landsat images these continuities are apparent. However, some critical information cannot be obtained through remote sensing, and several characteristics of the Landsat MSS impose limitations on the acquisition of diagnostic data. Some of these limitations can be overcome by designing satellite systems specifically for geologic purposes; but, to be most effective, remote-sensing data must still be combined with data from field surveys and laboratory tests, the techniques of the earlier twentieth century.

17. By using the word “interpretative” in line 40, the author is indicating which of the following?

(A) Some maps are based more on data from aerial photography than on data from field operations.

(B) Some maps are based almost exclusively on laboratory measurements.

(C) Some maps are based on incomplete data from field observations.

(D) Some maps show only large geologic features.(C)

(E) Some maps can be three-dimensional.

18. With which of the following statements about geologic mapping would the author be most likely to agree?

(A) Geologic mapping is basically an art and not a science.

(B) Geologic mapping has not changed significantly since the early 1960’s.

(C) Geologic mapping will have limited practical applications until remote-sensing systems are perfected.

(D) A developmental milestone in geologic mapping was reached in 1972.(D)

(E) Without the present variety of remote-sensing techniques, geologic mapping could not be done.

19. According to the passage, measurements of which of the following can be provided by the optomechanical scanner but not by visible-light photography?

(A) The amount of visible light reflected from oceans

(B) The density of foliage in remote areas on the Earth’s surface

(C) Daily temperature changes of areas on the Earth’s surface

(D) The degree of radioactivity emitted by exposed rocks on the Earth’s surface(C)

(E) Atmospheric conditions over large landmasses

20. It can be inferred from the passage that a major disadvantage of photographic imaging in geologic mapping is that such photography

(A) cannot be used at night

(B) cannot focus on the details of a geologic area

(C) must be chemically processed

(D) is always enhanced by digital reconstruction(C)

(E) cannot reflect changes over extended periods of time

21. It can be inferred from the passage that Landsat images differ from conventional geologic maps in that Landsat images

(A) reveal the exact size of petroleum deposits and ore deposits

(B) indicate the continuity of features that might not otherwise be interpreted as continuous

(C) predict the movements of glaciers

(D) provide highly accurate data about the occurrence of mineral deposits(B)

(E) reveal the integrity of the media in which petroleum deposits and ore deposits are found

22. The passage provides information about each of the following topics EXCEPT:

(A) the principal method of geologic remote sensing prior to the mid-1960’s

(B) some of the phenomena measured by digital multi-spectral images in remote sensing

(C) some of the practical uses of regional geologic maps

(D) the kinds of problems that are difficult to solve solely through conventional methods of geologic mapping(E)

(E) the specific limitations of the Landsat multi-spectral scanner

23. The passage suggests which of the following about the “conventional methods” mentioned in line 29?

(A) They consist primarily of field surveys and laboratory measurements.

(B) They are not useful in providing information necessary for reconstructing geologic evolution.

(C) They have rarely been used by geologists since 1972.

(D) They are used primarily to gather compositional information about geologic features.(A)

(E) They are limited primarily because of difficulties involved in interpreting film images.




  1. Modern archaeological finds can


Modern archaeological finds can still contribute much to the study of ancient literature. For example, forty years ago a survey of the early Greek dramatist Aeschylus’ plays would have started with The Suppliant Women. Many factors internal to the play, but perhaps most especially the prominence of the chorus (which in this play has the main role), led scholars to consider it one of Aeschylus’ earlier works. The consensus was that here was a drama truly reflecting an early stage in the evolution of tragedy out of choral lyric. The play was dated as early as the 490’s B.C., in any event (in any event: 无论如何), well before Aeschylus’ play The Persians of 472 B.C. Then, in 1952, a fragment of papyrus found at Oxyrhynchus was published stating the official circumstances and results of a dramatic contest. The fragment announced that Aeschylus won first prize with his Danaid tetralogy, of which The Suppliant Women is the opening play, and defeated Sophocles in the process. Sophocles did not compete in any dramatic contest before 468 B.C., when he won his first victory. Hence, except by special pleading (e. g., that the tetralogy was composed early in Aeschylus’ career but not produced until the 460’s B.C.), the Danaid tetralogy must be put after 468 B.C. In addition, a few letters in the fragment suggest the name Archedemides, archon in 463 B.C., thus perhaps tying the plays to that precise date, almost exactly halfway between Aeschylus’ Seven Against Thebes of 467 B.C. and his Oresteia.

The implication of the papyrus administered a severe shock to the vast majority of classical scholars, who had confidently asserted that not only the role of the chorus but also language, metrics, and characterization all pointed to an early date. The discovery has resulted in no less than a total reevaluation of every chronological criterion that has been applied to or derived from Aeschylus’ plays. The activity has been brisk, and a new creed has now spread. The prominence of the chorus in The Suppliant Women now is seen not as a sign of primitivism but as analogous to the massive choral songs of the Oresteia. Statistics have been formulated, or reformulated, to show that stylistically The Suppliant Women does actually occupy a position after The Persians and Seven Against Thebes, which now become the “primitive” plays, and before the Oresteia. While the new doctrine seems almost certainly correct, the one papyrus fragment raises the specter that another may be unearthed, showing, for instance, that it was a posthumous production of the Danaid tetralogy which bested Sophocles, and throwing the date once more into utter confusion. This is unlikely to happen, but it warns us that perhaps the most salutary feature of the papyrus scrap is its message of the extreme difficulty of classifying and categorizing rigidly the development of a creative artist.

21. The author of the passage focuses primarily on

(A) discussing a series of modern archaeological finds and their impact on the study of Greek literature

(B) recounting the effect of one archaeological find on modern ideas concerning a particular author’s work

(C) giving a definitive and coherent account of the chronology of a particular author’s work

(D) illustrating the many varieties of difficulties involved in establishing facts concerning ancient literature(B)

(E) determining the exact value of archaeological finds in relation to the history of ancient literature

22. With respect to the study of ancient literature, which of the following statements best expresses the author’s main point concerning modern archaeological finds?

(A) They can profoundly alter accepted views of ancient literary works, and can encourage flexibility in the way scholars look at the creative development of any artist.

(B) They can be severely shocking and can have a revivifying effect on the study of ancient literature, which has recently suffered from a lack of interest on the part of scholars.

(C) They can raise more questions than they answer and can be unreliable sources of information.

(D) They generally confirm scholars’ ideas about ancient literary works and allow them to dispense with inferences drawn from the works’ internal structure.(A)

(E) They often undermine scholarly consensus in certain areas and create utter confusion concerning an author’s work.

23. According to the passage, in the absence of definite knowledge concerning the dates of composition of ancient literary works, literary historians do which of the following when trying to establish the chronology of an author’s work?

(A) Make assumptions about a single work’s date of composition if such assumptions would not seriously affect interpretations of other works by the same author.

(B) Draw inferences concerning the date of a work’s composition based on evidence internal to that work and on the author’s other works.

(C) Ignore the date of a work’s composition which is supplied by archaeological research when literary factors internal to the work contradict that date.

(D) Refrain from speculation concerning a work’s date of composition unless archaeological finds produce information concerning it.(B)

(E) Estimate the date of a work’s composition without attempting to relate it to the author’s development as an artist.

24. It can be inferred from the passage that which of the following plays or groups of plays is considered the latest in the date of its composition?

(A) The Persians

(B) The Danaid tetralogy

(C) The Oresteia

(D) Seven Against Thebes(C)

(E) The Suppliant Women

25. With which of the following statements regarding the chronological criteria mentioned in line 33-34 would the author be most likely to agree?

(A) Such criteria, whether applied to or derived from the plays, should only be used to confirm already existing knowledge.

(B) Such criteria, although derived from reliable external and internal evidence, should be changed continually to avoid rigidity in thinking.

(C) Such criteria, based on statistical analysis, are inherently more reliable than those of forty years ago.

(D) Such criteria, even when unsupported by external evidence, can resolve most questions.(E)

(E) Such criteria, based on often ambiguous internal evidence, can lead to erroneous reconstructions of the chronology of an author’s work.

26. The author’s attitude toward the “activity” mentioned in line 35 and its consequences can best be described as one of

(A) amused tolerance

(B) mocking envy

(C) grave doubt

(D) angry disapproval(A)

(E) unrestrained enthusiasm

27. The allusion to the hypothetical papyrus fragment in line 45-49 does which of the following?

(A) Supports an argument concerning the date of The Suppliant Women.

(B) Refutes the views of the majority of scholars concerning the Oxyrhynchus papyrus find.

(C) Predicts the future results of archaeological research proposed in the passage.

(D) Undermines the validity of the currently accepted chronology of Aeschylus’ works.(E)

(E) Qualifies (To modify, limit, or restrict, as by giving exceptions.) the author’s agreement with the “new creed” developed since the Oxyrhynchus papyrus find.




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