托福阅读真题+题目+答案：Post-Pleistocene Extinctions in the New World

托福阅读真题+题目+答案：Post-Pleistocene Extinctions in the New World

The spread of human hunting-and-gathering societies over the New World (the land area now known as North and South America) that began about 12,000 years ago, at the end of the last glacial period, coincided with the extinction of many animal species, and by about 10,000 years ago all or most of the mammoths, mastodons, long-horned bison, tapirs, horses, giant ground sloths, dire wolves, camels, and many other creatures had disappeared. Extinction is, of course, a natural evolutionary development and can be accounted for by known biological processes.?But the number of animal species that became extinct in the New World, and their apparently rapid rate of extinction after humans arrived,?have led some to conclude that human hunters forced many New World animals into extinction shortly after the Pleistocene epoch (a glacial period lasting from 1.8 million to about 11,000 years ago).?This hypothesis is referred to as the overkill model.

1.Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaning in important ways or leave out essential information.

A.Many large animal species became extinct between 12,000 and 10,000 years ago, at the same time as hunting-and-gathering societies expanded into the New World.

B.By 10,000 years ago, hunting-and-gathering societies that spread into North and South America had hunted many large animal species to the point of extinction.

C.New World animal species that became extinct between 12.000 and 10,000 years ago included mammoths, mastodons, long-horned bison, tapirs, horses, and others.

D.Many animal species had disappeared by the end of the last glacial period, just before the arrival of humans in the New World.

But humans may have had little or nothing to do with these extinctions.?Some big-game species such as the mastodon lived in the southern and eastern parts of North America while humans were there and are known to have died out shortly after the end of the Pleistocene, but their bones have rarely been found in association with evidence of human activities.?Donald Grayson and David Meltzer note that only two animals that became extinct-the mammoth and the mastodon-are known from Clovis, the oldest recognized archaeological culture in America, with sites dated from 11.500 to 10,000 years ago, and of all the Clovis sites, only fourteen have this association between an extinct animal and Clovis artifacts. Perhaps even more significant, game species were not the only ones to die out.?Grayson has shown that numerous species of birds also became extinct at this time, and it is difficult to believe that humans played any role in these extinctions.?Finally we might also note that there is no archaeological evidence that the hunting practices most likely to lead to animal extinctions were ever used during the period, some 10,000 to 8,000 years ago, when most of the larger species became extinct.?Thus it would seem that at least some larger animals became extinct without much human assistance.

2.Which of the following is presented in paragraph 2 as a possible reason for thinking that the extinction of the mastodon may be unrelated to human activity?

A.Mastodons became extinct before the Clovis culture emerged.

B.Mastodon remains are less common than mammoth remains at Clovis sites.

C.Clovis artifacts have been found at relatively few sites with mastodon remains.

D.Mastodons lived in parts of North America that were not inhabited by humans.

3.All of the following are presented in paragraph 2 as reasons for thinking that humans had little or nothing to do with the post-Pleistocene extinctions EXCEPT:

A.Archaeological sites suggest that Clovis populations were too small to destroy many animals.

B.There is no evidence that humans had hunting methods capable of causing extinction.

C.The remains of only two species that became extinct have been found at Clovis sites.

D.Many bird species became extinct at the same time that game animals did.

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