21.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.
22.The methods that a community devises to perpetuate itself come into being to preserve aspects of the cultural legacy that that community perceives as essential.
23.Because the potential hazards pollen grains are subject to as they are transported over long distances are enormous，windpollinated plants have，in the view above，compensated for the ensuing loss of pollen through happenstance by virtue of producing an amount of pollen that is one to three orders of magnitude greater than the amount produced by species pollinated by insects.
24.For example，the spiral arrangement of scale-bract complexes on ovule-bearing pine cones，where the female reproductive organs of conifers are located，is important to the production of airflow patterns that spiral over the cone’s surfaces，thereby passing airborne pollen from one scale to the next.
25.It was not the change in office technology，but rather the separation of secretarial work， previously seen as an apprenticeship for beginning managers，from administrative work that in the 1880’s created a new class of "dead-end" jobs，thenceforth considered "women’s work."
26.The increase in the numbers of married women employed outside the home in the twentieth century had less to do with the mechanization of housework and an increase in leisure time for these women than it did with their own economic necessity and with high marriage rates that shrank the available pool of single women workers，previously，in many cases，the only women employers would hire.
27.In order to understand the nature of the ecologist’s investigation，we may think of the density-dependent effects on growth parameters as the "signal" ecologists are trying to isolate andinterpret，one that tends to make the population increase from relatively low values or decrease from relatively high ones，while the density-independent effects act to produce "noise" in the population dynamics.
28.But the play’s complex view of Black self-esteem and human solidarity as compatible is no more "contradictory" than Du Bois’ famous，well-considered ideal of ethnic self-awareness coexisting with human unity，or Fanon’s emphasis on an ideal internationalism that also accommodates national identities and roles.
29.Inheritors of some of the viewpoints of early twentieth-century Progressive historians such as Beard and Becker，these recent historians have put forward arguments that deserve evaluation.
30.Despite these vague categories，one should not claim unequivocally that hostility between recognizable classes cannot be legitimately observed.
31.Yet those who stress the achievement of a general consensus among the colonists cannot fully understand that consensus without understanding the conflicts that had to be overcome or repressed in order to reach it.
32.It can be inferred from the passage that the author would be most likely to agree with which of the following statements regarding socioeconomic class and support for the rebel and Loyalist causes during the American Revolutionary War?
33. Although it has been possible to infer from the goods and services actually produced what manufactures and servicing trades thought their customers wanted，only a study of relevant personal documents written by actual consumers will provide a precise picture of who wanted what.
34.Such philosophical concerns as the mind-body problem or，more generally，the nature of human knowledge they believe，are basic human questions whose tentative philosophical solutions have served as the necessary foundations on which all other intellectual speculation has rested.
35.The idea of an autonomous discipline called "philosophy，" distinct from and sitting in judgment on such pursuits as theology and science turns out，on close examination，to be of quite recent origin.
36.But the recent discovery of detailed similarities in the skeletal structure of the flippers in all three groups undermines the attempt to explain away
superficial resemblance as due to convergent evolution-the independent development
of similarities between unrelated groups in response to similar environmental pressures.
37.Human genes contain too little information even to specify which hemisphere of the brain each of a human’s 10’’ neurons should occupy，let alone the hundreds of connections that each neuron makes.
38.These questions are political in the sense that the debate over them will inevitably be less an exploration of abstract matters in a spirit of disinterested inquiry than an academic power struggle in which the careers and professional fortunes of many women scholars-only now entering the academic profession in substantial numbers-will be at stake ， and with them the chances for a distinctive contribution to humanistic understanding，a contribution that might be an important influence against sexism in our society.
39.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.
40.Recently some scientists have concluded that meteorites found on Earth and long believed to have a Martian origin might actually have been blasted free of Mars’s gravity by the impact on Mars of other meteorites.