『新东方在线托福听力』为托福考生准备了ETS托福TPO/Official 54 Passage 2阅读练习，TPO/Official 54 Passage 2原文答案解析，TPO/Official 54 Passage 2阅读原文练习音频翻译。

托福TPO/Official 54 Passage 2阅读原文题目答案及解析-新东方托福官方网校手机版

数千年前的北美，它所有的大型动物，如猛犸象和巨熊，都消失了。

Thousands of years ago, in North America’s past, all of its megafauna—large mammals such as mammoths and giant bears—disappeared.

对这一事件提出的一种解释是，当美国人首次从亚洲迁徙过来时，他们就开始捕猎大型动物直至其灭绝。

One proposed explanation for this event is that when the first Americans migrated over from Asia, they hunted the megafauna to extinction.

他们被称为克洛维斯族人，他们的独特的矛头是第一次被发现，能够利用这种食物来源来扩张人口并迅速填满整个大陆。

These people, known as the Clovis society after a site where their distinctive spear points were first found, would have been able to use this food source to expand their population and fill the continent rapidly.

然而，许多科学家反对这种“更新世 ——大约250万至11700年前——人类首次出现在地球上过度捕杀”的假说。

Yet many scientists argue against this “Pleistocenethe period between about 2.5 million and 11,700 years ago during which humans first appeared on Earth overkill” hypothesis.

现代人的确有能力对动物产生非常剧烈的影响，但古代人仅仅拥有石矛，也同样能让无数物种灭绝？

Modern humans have certainly been capable of such drastic effects on animals, but could ancient people with little more than stone spears similarly have caused the extinction of numerous species of animals?

大约在公元前11000年整个美洲的更新世晚期，在美洲活动的古印第安人出现和扩张之后不久，35个属或物种群（以及许多单个物种）在北美灭绝了（27个属完全消失，另外8个属也灭绝了，只存在于北美以外的区域）。

Thirty-five genera or groups of species (and many individual species) suffered extinction in North America around 11,000 B.C., soon after the appearance and expansion of Paleo-Indiansa group of hunters active in America during the late Pleistocene throughout the Americas (27 genera disappeared completely, and another 8 became locally extinct, surviving only outside North America).

尽管在更新世末期气候发生了变化，但变暖的趋势以前就出现过。

Although the climate changed at the end of the Pleistocene, warming trends had happened before.

在过去的40万年中，尽管发生了这些变化，但像11000年前那样的大型哺乳动物大规模灭绝的时期从来没有发生过。

A period of massive extinction of large mammals like that seen about 11,000 years ago had not occurred during the previous 400,000 years, despite these changes.

在11000年前，美洲与以前唯一明显的区别是捕猎这些大型哺乳动物的人类猎手也存在。

The only apparently significant difference in the Americas 11,000 years ago was the presence of human hunters of these large mammals.

Was this coincidence or cause-and-effect?

生态学家保罗·马丁一直支持将更新世末期大型哺乳动物的灭绝与人类捕猎相联系的模型。

Ecologist Paul S.Martin has championed the model that associates the extinction of large mammals at the end of the Pleistocene with human predation.

他与研究人员莫西曼共同撰写了一项研究，其中一个计算机模型显示，在大约300年的时间里，在适当的条件下，12000年前即使只有少量的猎人涌入贝林吉亚东部，也有可能会波浪式蔓延到北美，消灭猎物以满足其不断增长的人口。

With researcher J.E.Mosimann, he has co-authored a work in which a computer model showed that in around 300 years, given the right conditions, a small influx of hunters into eastern Beringia 12,000 years ago could have spread across North America in a wave and wiped out game animals to feed their burgeoning population.

研究人员以多种方式运行这个模型，总是从11500年前加拿大阿尔贝塔省埃德蒙顿的100人开始。

The researchers ran the model several ways, always beginning with a population of 100 humans in Edmonton, in Alberta, Canada, at 11,500 years ago.

假设北美最初的大型野生动物种群（7500万只-1亿5000万只）不同，人类定居者的种群增长率（0.65%-3.5%）也不同，并且死亡率也不同，莫西曼和马丁得出了从人类最初接触大型野生动物，到它们灭绝的时间数据，大约在279-1157年之间。

Assuming different initial North American big-game-animal populations (75–150 million animals) and different population growth rates for the human settlers (0.65%–3.5%), and varying kill rates, Mosimann and Martin derived figures of between 279 and 1,157 years from initial contact to big-game extinction.

许多学者继续支持这过度捕杀的模型。

Many scholars continue to support this scenario.

例如，地质学家拉里·阿根布罗德绘制了那个时期克洛维斯遗址的位置图，并绘制了在考古和纯古生物学背景下发现猛犸象遗骸的遗址分布图。

For example, geologist Larry Agenbroad has mapped the locations of dated Clovis sites alongside the distribution of dated sites where the remains of wooly mammoths have been found in both archaeological and purely paleontological contexts.

这些分布具有显著的同步性（在同时发生）。

These distributions show remarkable synchronicity (occurrence at the same time).

There are, however, many problems with this model.

最明显的问题就是，虽然有令人印象深刻的遗址，却只有很少的考古学证据来支持。

Significantly, though a few sites are quite impressive, there really is very little archaeological evidence to support it.

马丁本人在1982年撰文承认了证据不足，比如，当时在克洛维斯遗址中只发现了38头猛犸象的残骸。

Writing in 1982, Martin himself admitted the paucity of evidence; for example, at that point, the remains of only 38 individual mammoths had been found at Clovis sites.

在此后的几年间，鲜有其它猛犸象被发现；仍有不到20个克洛维斯遗址，其中发现了一个或多个猛犸象的遗骸，这在数百万猛犸象中占有极小比例，远低于过度捕杀场景所预计的。

In the years since, few additional mammoths have been added to the list; there are still fewer than 20 Clovis sites where the remains of one or more mammoths have been recovered, a minuscule proportion of the millions that necessarily would have had to have been slaughtered within the overkill scenario.

尽管马丁声称证据的缺乏实际上能证明他的模型，理由是人类的扩张和动物的灭绝发生得太快了所以证据稀少，但这一论证似乎站不住脚。

Though Martin claims the lack of evidence actually supports his model—the evidence is sparse because the spread of humans and the extinction of animals occurred so quickly—this argument seems weak.

正如考古学家唐纳德·格雷森指出的那样，在其它一些因人类猎人的迅速蔓延而导致灭绝的考古证据是十分丰富的。例如，新西兰大型无翼鸟恐鸟灭绝后留下了大量的遗骸。

As archaeologist Donald Grayson points out, in other cases where extinction resulted from the quick spread of human hunters—for example, the extinction of the moa, the large flightless bird of New Zealand—archaeological evidence in the form of remains is abundant.

格雷森还表明，没有清楚的证据表明，在更新世晚期的美洲，所有或者大多数大型食草动物在克洛维斯人出现后都灭绝了。

Grayson has also shown that the evidence is not so clear that all or even most of the large herbivores in late Pleistocene America became extinct after the appearance of Clovis.

在35个灭绝的属中，只能确定其中8个属的灭绝日期在12000年到10000年之间。

Of the 35 extinct genera, only 8 can be confidently assigned an extinction date of between 12,000 and 10,000 years ago.

格雷森认为，在公元前12000年之前，至少在克洛维斯人在美国西部出现的前半个世纪，许多较老的属可能已经灭绝。

Many of the older genera, Grayson argues, may have succumbed before 12,000 B.C., at least half a century before the Clovis showed up in the American West.

The word “proposed” in the passage is closest in meaning to

Why does the author compare Modern humans with ancient people?

In using the word “coincidence” in the passage, the author refers to events that occurred

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.

Which of the following best describes the results of the research discussed in paragraph 4?

Which of the following statements about Larry Agenbroad’s work is implied in the discussion in paragraph 5?

According to paragraph 6, which of the following statements challenges the view that hunting by humans caused the extinctions of North American megafauna?

In paragraph 7, why does the author mention that there is abundant archaeological evidence for the extinction of the New Zealand moa?

Look at the four squares  that indicate where the following sentence could be added to the passage. One possible nonhuman cause—weather cycles—is not consistent with what scientists know about the timing of the extinctions.  Where would the sentence best fit? Click on a square  to add the sentence to the passage.

Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some sentences do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points.

Overkill of the North American Megafauna Thousands of years ago, in North America’s past, all of its megafauna—large mammals such as mammoths and giant bears—disappeared. One proposed explanation for this event is that when the first Americans migrated over from Asia, they hunted the megafauna to extinction. These people, known as the Clovis society after a site where their distinctive spear points were first found, would have been able to use this food source to expand their population and fill the continent rapidly. Yet many scientists argue against this “Pleistocene, the period between about 2.5 million and 11,700 years ago during which humans first appeared on Earth, overkill” hypothesis. Modern humans have certainly been capable of such drastic effects on animals, but could ancient people with little more than stone spears similarly have caused the extinction of numerous species of animals? Thirty-five genera or groups of species (and many individual species) suffered extinction in North America around 11,000 B.C., soon after the appearance and expansion of Paleo-Indians, a group of hunters active in America during the late Pleistocene, throughout the Americas (27 genera disappeared completely, and another 8 became locally extinct, surviving only outside North America).  Although the climate changed at the end of the Pleistocene, warming trends had happened before.  A period of massive extinction of large mammals like that seen about 11,000 years ago had not occurred during the previous 400,000 years, despite these changes.  The only apparently significant difference in the Americas 11,000 years ago was the presence of human hunters of these large mammals.  Was this coincidence or cause-and-effect? We do not know. Ecologist Paul S.Martin has championed the model that associates the extinction of large mammals at the end of the Pleistocene with human predation. With researcher J.E.Mosimann, he has co-authored a work in which a computer model showed that in around 300 years, given the right conditions, a small influx of hunters into eastern Beringia 12,000 years ago could have spread across North America in a wave and wiped out game animals to feed their burgeoning population. The researchers ran the model several ways, always beginning with a population of 100 humans in Edmonton, in Alberta, Canada, at 11,500 years ago. Assuming different initial North American big-game-animal populations (75–150 million animals) and different population growth rates for the human settlers (0.65%–3.5%), and varying kill rates, Mosimann and Martin derived figures of between 279 and 1,157 years from initial contact to big-game extinction. Many scholars continue to support this scenario. For example, geologist Larry Agenbroad has mapped the locations of dated Clovis sites alongside the distribution of dated sites where the remains of wooly mammoths have been found in both archaeological and purely paleontological contexts. These distributions show remarkable synchronicity (occurrence at the same time). There are, however, many problems with this model. Significantly, though a few sites are quite impressive, there really is very little archaeological evidence to support it. Writing in 1982, Martin himself admitted the paucity of evidence; for example, at that point, the remains of only 38 individual mammoths had been found at Clovis sites. In the years since, few additional mammoths have been added to the list; there are still fewer than 20 Clovis sites where the remains of one or more mammoths have been recovered, a minuscule proportion of the millions that necessarily would have had to have been slaughtered within the overkill scenario. Though Martin claims the lack of evidence actually supports his model—the evidence is sparse because the spread of humans and the extinction of animals occurred so quickly—this argument seems weak. And how could we ever disprove it? As archaeologist Donald Grayson points out, in other cases where extinction resulted from the quick spread of human hunters—for example, the extinction of the moa, the large flightless bird of New Zealand—archaeological evidence in the form of remains is abundant. Grayson has also shown that the evidence is not so clear that all or even most of the large herbivores in late Pleistocene America became extinct after the appearance of Clovis. Of the 35 extinct genera, only 8 can be confidently assigned an extinction date of between 12,000 and 10,000 years ago. Many of the older genera, Grayson argues, may have succumbed before 12,000 B.C., at least half a century before the Clovis showed up in the American West.