gre阅读练习每日一篇(十三)

　　掌握了gre阅读里的长难句，到了实战演习的时候了。gre阅读练习每日一篇帮助gre考生循序渐进地进行练习和总结。希望gre考生在进行gre阅读练习时，也按着考试时候的时间规定自己的练习，这样才能有效果。

　　By the time the American colonists took up arms against Great Britain in order to secure their independence, the institution of Black slavery was deeply entrenched. But the contradiction inherent in this situation was, for many, a source of constant embarrassment. It always appeared a most iniquitous scheme to me, Abigail Adams wrote her husband in 1774, to fight ourselves for what we are daily robbing and plundering from those who have as good a right to freedom as we have.

　　Many Americans besides Abigail Adams were struck by the inconsistency of their stand during the War of Independence, and they were not averse to making moves to emancipate the slaves. Quakers and other religious groups organized antislavery societies, while numerous individuals manumitted their slaves. In fact, within several years of the end of the War of Independence, most of the Eastern states had made provisions for the gradual emancipation of slaves.

　　17. Which of the following best states the central idea of the passage?

　　 The War of Independence produced among many Black Americans a heightened consciousness of the inequities in American society.

　　 The War of Independence strengthened the bonds of slavery of many Black Americans while intensifying their desire to be free.

　　 The War of Independence exposed to many Americans the contradiction of slavery in a country seeking its freedom and resulted in efforts to resolve that contradiction.

　　 The War of Independence provoked strong criticisms by many Americans of the institution of slavery, but produced little substantive action against it.

　　 The War of Independence renewed the efforts of many American groups toward achieving Black emancipation.

　　18. The passage contains information that would support which of the following statements about the colonies before the War of Independence?

　　 They contained organized antislavery societies.

　　 They allowed individuals to own slaves.

　　 They prohibited religious groups from political action.

　　 They were inconsistent in their legal definitions of slave status.

　　 They encouraged abolitionist societies to expand their influence.

　　19. According to the passage, the War of Independence was embarrassing to some Americans for which of the following reasons?

　　I. It involved a struggle for many of the same liberties that Americans were denying to others.

　　II. It involved a struggle for independence from the very nation that had founded the colonies.

　　III. It involved a struggle based on inconsistencies in the participants conceptions of freedom.

　　 I only

　　 II only

　　 I and II only

　　 I and III only

　　 I, II, and III

　　20. Which of the following statements regarding American society in the years immediately following the War of Independence is best supported by the passage?

　　 The unexpected successes of the antislavery societies led to their gradual demise in the Eastern states.

　　 Some of the newly independent American states had begun to make progress toward abolishing slavery.

　　 Americans like Abigail Adams became disillusioned with the slow progress of emancipation and gradually abandoned the cause.

　　 Emancipated slaves gradually were accepted in the Eastern states as equal members of American society.

　　 The abolition of slavery in many Eastern states was the result of close cooperation between religious groups and free Blacks.

　　The evolution of sex ratios has produced, in most plants and animals with separate sexes, approximately equal numbers of males and females. Why should this be so? Two main kinds of answers have been offered. One is couched in terms of advantage to population. It is argued that the sex ratio will evolve so as to maximize the number of meetings between individuals of the opposite sex. This is essentially a group selection argument. The other, and in my view correct, type of answer was first put forward by Fisher in 1930. This genetic argument starts from the assumption that genes can influence the relative numbers of male and female offspring produced by an individual carrying the genes. That sex ratio will be favored which maximizes the number of descendants an individual will have and hence the number of gene copies transmitted. Suppose that the population consisted mostly of females: then an individual who produced sons only would have more grandchildren. In contrast, if the population consisted mostly of males, it would pay to have daughters. If, however, the population consisted of equal numbers of males and females, sons and daughters would be equally valuable. Thus a one-to-one sex ratio is the only stable ratio; it is an evolutionarily stable strategy. Although Fisher wrote before the mathematical theory of games had been developed, his theory incorporates the essential feature of a gamethat the best strategy to adopt depends on what others are doing.

　　Since Fishers time, it has been realized that genes can sometimes influence the chromosome or gamete in which they find themselves so that the gamete will be more likely to participate in fertilization. If such a gene occurs on a sex-determining chromosome, then highly aberrant sex ratios can occur. But more immediately relevant to game theory are the sex ratios in certain parasitic wasp species that have a large excess of females. In these species, fertilized eggs develop into females and unfertilized eggs into males. A female stores sperm and can determine the sex of each egg she lays by fertilizing it or leaving it unfertilized. By Fishers argument, it should still pay a female to produce equal numbers of sons and daughters. Hamilton, noting that the eggs develop within their hostthe larva of another insectand that the newly emerged adult wasps mate immediately and disperse, offered a remarkably cogent analysis. Since only one female usually lays eggs in a given larva, it would pay her to produce one male only, because this one male could fertilize all his sisters on emergence. Like Fisher, Hamilton looked for an evolutionarily stable strategy, but he went a step further in recognizing that he was looking for a strategy.

　　21. The author suggests that the work of Fisher and Hamilton was similar in that both scientists

　　 conducted their research at approximately the same time

　　 sought to manipulate the sex ratios of some of the animals they studied

　　 sought an explanation of why certain sex ratios exist and remain stable

　　 studied game theory, thereby providing important groundwork for the later development of strategy theory

　　 studied reproduction in the same animal species

　　22. It can be inferred from the passage that the author considers Fishers work to be

　　 fallacious and unprofessional

　　 definitive and thorough

　　 inaccurate but popular, compared with Hamiltons work

　　 admirable, but not as up-to-date as Hamiltons work

　　 accurate, but trivial compared with Hamiltons work

　　23. The passage contains information that would answer which of the following questions about wasps?

　　I. How many eggs does the female wasp usually lay in a single host larva?

　　II. Can some species of wasp determine sex ratios among their offspring?

　　III. What is the approximate sex ratio among the offspring of parasitic wasps?

　　 I only

　　 II only

　　 III only

　　 I and II only

　　 II and III only

　　24. It can be inferred that the author discusses the genetic theory in greater detail than the group selection theory primarily because he believes that the genetic theory is more

　　 complicated

　　 accurate

　　 popular

　　 comprehensive

　　 accessible

　　25. According to the passage, successful game strategy depends on

　　 the ability to adjust ones behavior in light of the behavior of others

　　 ones awareness that there is safety in numbers

　　 the degree of stability one can create in ones immediate environment

　　 the accuracy with which one can predict future events

　　 the success one achieves in conserving and storing ones resources

　　26. It can be inferred from the passage that the mathematical theory of games has been

　　 developed by scientists with an interest in genetics

　　 adopted by Hamilton in his research

　　 helpful in explaining how genes can sometimes influence gametes

　　 based on animals studies conducted prior to 1930

　　 useful in explaining some biological phenomena

　　27. Which of the following is NOT true of the species of parasitic wasps discussed in the passage?

　　 Adult female wasps are capable of storing sperm.

　　 Female wasps lay their eggs in the larvae of other insects.

　　 The adult female wasp can be fertilized by a male that was hatched in the same larva as herself.

　　 So few male wasps are produced that extinction is almost certain.

　　 Male wasps do not emerge from their hosts until they reach sexual maturity.

答案：17-27：CBABCDBBAED