冲刺班结班测试

* Common and easily accessible resources (prey for predators or hosts for parasites should be, all other things being equal, used frequently, yet in some environments apparently accessible and suitable resources remain ______.

* Even though the authors repeatedly ______ their own shrewdness, they show a remarkable credulousness toward far-fetched ideas such as carbon-eating trees and cloud-making machinery.

* The (i)______ of molecular oxygen on Earth-sized planets around other stars in the universe would not be (ii)______ sign of life: molecular oxygen can be a signature of photosynthesis (a biotic process) or merely of the rapid escape of water from the upper reaches of a planetary atmosphere (an abioticprocess).

最少选择 2 项，最多选择 2 项

* In reviewing cases decided by lower courts, Supreme Court justices search for precedents to justify their arguments. Reliance on precedent(i)______ judicial restraint: the precedent (ii)______ a judge's ability to determine the outcome of a case in a way that he or she might choose if there were no precedent.

最少选择 2 项，最多选择 2 项

* As he has matured as a scholar, Felmar has come to see the merit of qualification. His conclusions, which early in his career he (i)______, are now often (ii)______.

最少选择 2 项，最多选择 2 项

* To pay for the extra spending under this international poverty plan, each American would have to contribute less than the cost of buying a premium cup of coffee once a week. But financial aid is not (i)______, and evenif the funding recommended here were to (ii)______, the grandest objectives may well remain unfulfilled. Nonetheless, carefully targeted aid can reward responsible governments, (iii)______ individual initiative, and alleviate suffering. Many will think that's worth a cup of coffee.

最少选择 3 项，最多选择 3 项

When Earth formed 4.6 billion years ago, the Sun burned only 70 percent as brightly as it does today. Yet geologic record contains no evidence for widespread glaciation until 2.3 billion years ago. Sagan and Mullen suggested in the 1970s that ammonia, a greenhouse gas, warmed early Earth's atmosphere, but subsequent research showed that the Sun's ultraviolet rays rapidly destroy ammonia in an oxygen-free environment, such as that of early Earth. Many scientists now attribute much of the warming of early Earth to oxygen-intolerant microbes—methanogens—that produce the greenhouse gas methane. The methanogen hypothesis could help to explain the first global ice age: 2.3 billion years ago, Earth's atmosphere began to fill with oxygen produced by other microbes—cyanobacteria—causing methanogens to decline rapidly.

* Which of the following best describes the function of the highlighted sentence?

A. It refutes the possibility of a connection between two events previously thought to be related.

B. It describes how a hypothesis might account for the timing of a phenomenon described earlier in the passage.

C. It presents evidence that casts doubt on a statement made in the first sentence of the passage.

D. It clarifies a distinction between two related hypotheses.

E. It introduces findings that challenge a dominant explanation for a particular phenomenon.

* Which of the following can be inferred from the passage about methanogens?

A. Methanogens must have appeared on Earth later than 2.3 billion years ago.

B. Methanogens must have been much more prevalent in some regions of the early Earth than in others.

C. Methanogens produce a greenhouse gas that is more susceptible to destruction by the Sun's ultraviolent rays than is ammonia.

D. Methanogens could not have thrived in early Earth's atmosphere without the presence of ammonia.

E. Methanogens would have had a less significant effect on early Earth's atmosphere if they had evolved after the appearance of cyanobacteria.

Recent studies of sediment in the North Atlantic's deep waters reveal possible cyclical patterns in the history of Earth'sclimate. The rock fragments in these sediments are too large to have beentransported there by ocean currents; they must have reached their presentlocations by traveling in large icebergs that floated long distances from theirpoint of origin before melting. Geologist Gerard Bond noticed that some of the sediment grains were stained with iron oxide, evidence that they originated inlocales where glaciers had overrun outcrops of red sandstone. Bond's detailed analysis of deep-water sediment cores showed changes in the mix of sediment sources over time: the proportion of these red-stained grains fluctuated backand forth from lows of 5 percent to highs of about 17 percent, and these fluctuations occurred in a nearly regular 1,500-year cycle.

Bond hypothesized that the alternating cycles might be evidence of changes in ocean-water circulation and therefore in Earth's climate. He knew that the sources of the red-stained grains were generally closer to the North Pole thanwere the places yielding a high proportion of “clean” grains. At certain times,apparently, more icebergs from the Arctic Ocean in the far north were travelingsouth well into the North Atlantic before melting and shedding their sediment.

Ocean waters are constantly moving, and water temperature is both a causeand an effect of this movement. As water cools, it becomes denser and sinks tothe ocean's bottom. During some periods, the bottom layer of the world's oceans comes from cold, dense water sinking in the far North Atlantic. This causes the warm surface waters of the Gulf Stream to be pulled northward. Bond realized that during such periods, the influx of these warm surface waters into northern regions could cause a large proportion of the icebergs that bear red grains tomelt before traveling very far into the North Atlantic. But sometimes theocean's dynamic changes, and waters from the Gulf Stream do not travel northward in this way. During these periods, surface waters in the North Atlantic would generally be colder, permitting icebergs bearing red-stained grains to travel farther south in the North Atlantic before melting and depositing their sediment.

The onset of the so-called Little Ice Age (1300-1860), which followed the Medieval Warm Period of the eighth through tenth centuries, may represent themost recent time that the ocean's dynamic changed in this way. If ongoing climate-history studies support Bond's hypothesis of 1,500-year cycles, scientists may establish a major natural rhythm in Earth's temperatures that could then be extrapolated into the future. Because the midpoint of the Medieval Warm Period was about 850, an extension of Bond's cycles would place the midpoint of the next warm interval in the twenty-fourth century.

* According to the passage, which of the following is true of the rock fragments contained in the sediments studied by Bond?

A. The majority of them are composed of red sandstone.

B. They must have reached their present location over 1,500 years ago.

C. They were carried by icebergs to their present location.

D. Most of them were carried to their present location during a warm period in Earth's climatic history.

E. They are unlikely to have been carried to their present location during the Little Ice Age.

* In the final paragraph of the passage, the author is concerned primarily with

A. answering a question about Earth's climatic history

B. pointing out a potential flaw in Bond's hypothesis

C. suggesting a new focus for the study of ocean sediments

D. tracing the general history of Earth's climate

E. discussing possible implications of Bond's hypothesis

* According to the passage, Bond hypothesized that which of the following circumstances would allow red-stained sediment grains to reach more southerly latitudes?

A. Warm waters being pulled northward from the Gulf Stream.

B. Climatic conditions causing icebergs to melt relatively quickly.

C. Icebergs containing a higher proportion of iron oxide than usual.

D. The formation of more icebergs than usual in the far north.

E. The presence of cold surface waters in the North Atlantic.

* It can be inferred from the passage that in sediment cores from the North Atlantic's deep waters, the portions that correspond to the Little Ice Age

A. differ very little in composition from the portions that correspond to the Medieval Warm Period.

B. fluctuate significantly in composition between the portions corresponding to the 1300s and the portions corresponding to the 1700s.

C. would be likely to contain a proportion of red-stained grains closer to 17 percent than to 5 percent.

D. show a much higher proportion of red-stained grains in cores extracted from the far north of the North Atlantic than in cores extracted from further south.

E. were formed in part as a result of Gulf Stream waters having been pulled northward.

* The recent exhibition on Dadaism is nothing if not ______, for the visual arts are currently awash in Dadaism gestures and gambits of one variety or another.

最少选择 2 项，最多选择 2 项

* Despite the general ______ of Roman archaeological studies toward themajor cities and their monuments, archaeology has contributed much to a better understanding of rural developments in Roman territory.

* The potential reduction in water lost from the proposed reservoir from evaporation is ______ inconsequential: even the minimum projected reduction would save enough water to furnish the needs of a Denver-sized municipality.

* Our mass media are much more fascinated by bad ideas or the failure of good ones than by successes: we drown in bad news—tales of how things went wrong—but we have only the most ______ discussion on how they might go right.

New methods developed in genetic research have led taxonomists torevise their views on the evolutionary relationships between many species.Traditionally the relatedness of species has been ascertained by a close comparison of their anatomy. The new methods infer the closeness of any twospecies' relationship to each other directly from similarities between thespecies' genetic codes.

* Which of the following conclusions is best supported by the information?

A. The apparent degree of relatedness of some species, as determined by anatomical criteria, is not borne out by their degree of genetic similarity.

B. When they know the differences between two species’ genetic codes, taxonomists can infer what the observable anatomical differences between those species must be.

C. The degree to which individuals of the same species are anatomically similar is determined more by their genetic codes than by such environmental factors as food supply.

D. The traditional anatomical methods by which taxonomists investigated the relatedness of species are incapable of any further refinement.

E. Without the use of genetic methods, taxonomists would never be able to obtain any accurate information about species’ degrees of relatedness to one another.

Some historians question the widely held belief that continually improving education led to gradual African American empowerment in the southern United States from the late nineteenth century through the mid-twentieth century. They note that the development of Black educational institutions in the segregated South was never rapid or steady: disparities between Black and White schools sometimes grew in the early decades of the twentieth century. And African Americans' educational gains did not bring commensurate economic gains. Starting in the 1940s, even as Black and White schools in the South moved steadily toward equality, Black southerners remained politically marginalized and experienced systematic job discrimination. Although Black schools had achieved near parity with White schools in per capita spending and teachers' salaries by 1965, African Americans' income still lagged behind that of Whites. Nonetheless, educational progress did contribute toward economic and political empowerment. African Americans' campaigns to support Black schools fostered a sense of community, nurtured political determination, and often increased literacy. More significantly, politically outspoken Black newspapers achieved record circulation during the 1940s, just as the literacy rate among African Americans approached 90 percent. Finally, the leadership of the Civil Rights movement of the 1960s was composed largely of graduates of Black colleges.

* The passage suggests which of the following about the Civil Rights movement?

A. It gave rise to a rapid increase in the number of Black newspapers published in the South.

B. Its political effectiveness was greatly enhanced by the increased circulation of Black newspapers.

C. Its leadership benefited from improvements in education for African Americans.

D. It was the force primarily responsible for increasing per capita spending in Black schools.

E. It was responsible for changing many historians’ view of the relation between education and African American empowerment.

* The author of the passage refers to the fact that “disparities between Black and White schools sometimes grew in the early decades of the twentieth century” most likely in order to

A. support the argument that the economic struggles of southern Blacks were largely due to educational inequalities.

B. give an example of the differences between Black schools in the early part of the twentieth century and Black schools starting in the 1940s.

C. illustrate the unevenness of the progress made by Black schools in the southern United States.

D. help explain why Black remained politically marginalized and experienced systematic job discrimination in the segregated South.

E. provide evidence that educational progress was a precondition for economic progress in the segregated South.

* Which of the following best describes the purpose of the highlighted sentence?

A. It clarifies a point introduced in the preceding sentence.

B. It reiterates a point introduced in the first sentence of the passage.

C. It questions the accuracy of some of the evidence used to support the argument of the historians.

D. It introduces a perspective that runs contrary to the view of those who endorse the “belief.”

E. It qualifies the interpretation made by the historians.