『新东方在线托福阅读』为托福考生准备了ETS托福TPO/Official 39 Passage 2阅读练习：According to paragraph 6, scientists may never know if diseases contributed to the extinction of moa because真题题目及答案解析，TPO/Official 39 Passage 2阅读原文范文音频翻译

托福TPO/Official 39 Passage 2阅读原文According to paragraph 6, scientists may never know if diseases contributed to the extinction of moa because题目答案及解析-新东方托福官方网校手机版

在八千万年到八千五百万年之前，冈瓦纳大陆，也就是由现在的非洲、南极洲、澳洲和南美洲组成的巨大的大陆，分裂开了，因此导致了现在的新西兰和大陆块分开了。

Between 80 and 85 million years ago, Gondwanaland, a giant continent made up of what today is Africa, Antarctica, Australia, and South America, broke up, thus causing what is now New Zealand to become separated from the larger landmass.

在那次分裂之后，所有无法跨越海洋的巨大距离的生物都无法迁移到新西兰。

After the separation, any creature unable to cross a considerable distance of ocean could not migrate to New Zealand.

在这次分裂之后蛇和绝大多数的哺乳动物都进化了。

Snakes and most mammals evolved after the separation.

因此，当波利尼西亚定居者（毛利人）在大约一千多年前到达的时候，再也没有新西兰蛇了，飞到那里的蝙蝠和游到那里的海豹成了新西兰唯一的哺乳动物了。

Thus there are no New Zealand snakes, and bats, which flew there, and seals, which swam there, were the only mammals on New Zealand when Polynesian settlers (the Maori) arrived there about a thousand years ago.

当毛利人到达新西兰的时候，他们遇到的鸟都是已经进化了八千万年的，并且鸟类的哺乳动物捕食者都已经消失了。

When the Maori arrived in New Zealand, they encountered birds that had been evolving for 80 million years without the presence of mammalian predators.

这些动物中最引人注目的就是恐鸟了。

The most striking of these animals must have been moa.

尽管现在已经灭绝了，但当时恐鸟是一种巨大的没有翅膀的鸟，它有10英尺（3米）高，重达550磅（250千克）。

Now extinct, moa were gigantic wingless birds that stood as much as 10 feet (3 meters) tall and weighed as much as 550 pounds (250 kilograms).

它们因为多种多样的遗体残骸而出名，这些残骸包括蛋壳、蛋、少量木乃伊化的骨架、大量的尸骨和老的化石化的骨头。

They are known from a diverse array of remains including eggshells, eggs, a few mummified carcasses, vast numbers of bones, and some older fossilized bone.

恐鸟这一物种当今也被认作是占据了生态位，这种生态位在别处通常是由大型哺乳类食草动物占据的。

The species of moa that are currently recognized occupied ecological niches customarily filled elsewhere by large mammalian browsing herbivores.

它们有相对较低的繁殖率；很显然，它们通常一次只生一个蛋。

They may have had relatively low reproductive rates; apparently, they usually laid only one egg at a time.

有可能当库克船长在1769年第一次到达新西兰的时候，恐鸟（或者是至少恐鸟的一个物种）可能依然存在于新西兰南岛西部的偏远地区。

It seems possible that when Captain James Cook first visited New Zealand in 1769, moa (or at least one of the moa species) may have still survived in the remote areas in the western part of New Zealand’s South Island.

如果是这样的话，它们会是它们物种的最后几只了。

If so, these individuals would have been the last of their kind.

在恐鸟灭绝的时候，新西兰的气候状况是相对比较稳定的。

Climatic conditions in New Zealand appear to have been relatively stable over the period during which moa became extinct.

不同的因素可能共同会导致恐鸟的突然灭绝。

Different factors could have worked in concert to account for their abrupt disappearance.

当毛利人占据了新西兰后，那里的植被发生了巨大的变化，这个变化是不能轻易被气候的改变或者其他可能的因素所解释的。

Vegetation was considerably altered by the Maori occupation of New Zealand, a change not easily explained by climate variation or other possible factors.

森林和灌丛的燃烧可能会导致很多恐鸟物种主要栖息地的减少。

Forest and shrubland burning appears to have reduced the prime habitat of many moa species.

但是，大面积的森林起火是在大约七百年前开始的，现在的考古证据表明在那之前是狩猎恐鸟的最集中的时期。

However, the main forest burning started around 700 years ago, after what current archaeological evidence indicates was the most intensive stage of moa hunting.

尽管在新西兰南岛的东边有大面积的森林起火，在岛屿南部的绝大多数地区森林还是大面积存在的。

While there appears to have been extensive burning on the east side of New Zealand’s South Island, large forest tracts remained in the most southern part of the island.

因为大面积的栖息地破坏是在恐鸟数量已经大面积减少之后发生的，并且由于一些本可以庇护恐鸟的栖息地依然存在，因此其他的因素也会导致恐鸟的灭绝。

Because major habitat destruction seems to have occurred after moa populations already were depleted, and because some habitat that could have sheltered moa populations remained, it would seem that other factors were also at work in the extinction of these birds.

在岛屿南部，人类的狩猎是导致恐鸟数量下降的一个主要因素。

For South Island, human predation appears to have been a significant factor in the depletion of the population of moa.

在一个挖掘出来的毛利人古迹，恐鸟的尸体装满了六个铁路车厢。

At one excavated Maori site, moa remains filled six railway cars.

在最近在狩猎恐鸟的时期（900到600年前），毛利人口密度和人工制品的密度大幅度上升。

The density of Maori settlements and artifacts increased substantially at the time of the most intensive moa hunting (900 to 600 years ago).

在这个时期过后，毛利人口数量减少，并且社会转变成了更小的、数量也少了的聚居区。

This period was followed by a time of decline in the Maori population and a societal transition to smaller, less numerous settlements.

这种明显的下降符合了这种模式，也就是毛利人过度捕猎恐鸟产生的后果。

The apparent decline fits the pattern expected as a consequence of the Maori’s overexploitation of moa.

最终，毛利人把波利尼西亚鼠和狗引进了新西兰。

Finally, the Maori introduced the Polynesian rat and the dog to New Zealand.

这些潜在的巢猎食者的行为可能会导致恐鸟数量的减少而留不下什么直接的证据。

The actions of these potential nest predators could have reduced moa populations without leaving much direct evidence.

毛利人可能也不经意地带进了害虫和致病的有机体给家禽，这也会导致了恐鸟的灭绝。

The Maori may have also inadvertently brought pests and disease organisms in fowls, which could have crossed over to eradicate moa populations.

这种通过分析古老DNA来鉴别消失动物的过往疾病的可能性正在被研究。

The possibility of analyzing ancient DNA to identify past diseases of extinct animals is being explored.

但是，这些疾病的证据很难去直接通过古生态学和考古学的遗留物去辨别。

However, evidence of such diseases is difficult to determine directly from paleoecological or archaeological remains.

基于这些原因，很难去确定引入的致病有机体导致了恐鸟减少的可能性，但是潜在意义上来讲，这些是很重要的。

For these reasons, it is hard to determine the likelihood that introduced disease organisms were a cause of the decline of moa, but they are potentially significant.

尽管这些原因的最后一种依然只是推测，前两个原因是有明确的线索存在的。

While the last of these possible causes remains speculative, definite clues exist for the action of the first two causes.

恐鸟这个物种和它们的灭绝指出来了人类活动会使得物种变得非常脆弱这一生态问题，这些包括自然环境植被覆盖的改变、周围物理环境的改变、通过消灭一些物种并引入其他物种而造成的一个地区动植物群的改变。

The story of moa species and their demise raises ecological issues on the vulnerability of species to human-caused changes—including altered vegetative cover of the landscape, change in the physical environment, and modification of the flora and fauna of a region by eliminating some species and introducing others.

Paragraph 1 supports which of the following inferences about mammal evolution?

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

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

Why does the author provide the information that “Climatic conditions in New Zealand appear to have been relatively stable over the period during which moa became extinct”?

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

According to paragraph 4, why is forest burning considered only a partial explanation for the disappearance of moa?

Why does the author say that “At one excavated Maori site, moa remains filled six railway cars.”?

Paragraph 5 presents which of the following as evidence that hunting was one of the factors responsible for the decline of moa?

According to paragraph 6, scientists may never know if diseases contributed to the extinction of moa because

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

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.

Look at the four squares  that indicate where the following sentence could be added to the passage. Investigations of DNA recovered from these sources suggest that there were ten to fifteen moa species.  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.

The Extinction of Moa Between 80 and 85 million years ago, Gondwanaland, a giant continent made up of what today is Africa, Antarctica, Australia, and South America, broke up, thus causing what is now New Zealand to become separated from the larger landmass. After the separation, any creature unable to cross a considerable distance of ocean could not migrate to New Zealand. Snakes and most mammals evolved after the separation. Thus there are no New Zealand snakes, and bats, which flew there, and seals, which swam there, were the only mammals on New Zealand when Polynesian settlers (the Maori) arrived there about a thousand years ago. When the Maori arrived in New Zealand, they encountered birds that had been evolving for 80 million years without the presence of mammalian predators.  The most striking of these animals must have been moa.  Now extinct, moa were gigantic wingless birds that stood as much as 10 feet (3 meters) tall and weighed as much as 550 pounds (250 kilograms).  They are known from a diverse array of remains including eggshells, eggs, a few mummified carcasses, vast numbers of bones, and some older fossilized bone.  The species of moa that are currently recognized occupied ecological niches customarily filled elsewhere by large mammalian browsing herbivores. They may have had relatively low reproductive rates; apparently, they usually laid only one egg at a time. It seems possible that when Captain James Cook first visited New Zealand in 1769, moa (or at least one of the moa species) may have still survived in the remote areas in the western part of New Zealand’s South Island. If so, these individuals would have been the last of their kind. Climatic conditions in New Zealand appear to have been relatively stable over the period during which moa became extinct. Different factors could have worked in concert to account for their abrupt disappearance. Vegetation was considerably altered by the Maori occupation of New Zealand, a change not easily explained by climate variation or other possible factors. Forest and shrubland burning appears to have reduced the prime habitat of many moa species. However, the main forest burning started around 700 years ago, after what current archaeological evidence indicates was the most intensive stage of moa hunting. While there appears to have been extensive burning on the east side of New Zealand’s South Island, large forest tracts remained in the most southern part of the island. Because major habitat destruction seems to have occurred after moa populations already were depleted, and because some habitat that could have sheltered moa populations remained, it would seem that other factors were also at work in the extinction of these birds. For South Island, human predation appears to have been a significant factor in the depletion of the population of moa. At one excavated Maori site, moa remains filled six railway cars. The density of Maori settlements and artifacts increased substantially at the time of the most intensive moa hunting (900 to 600 years ago). This period was followed by a time of decline in the Maori population and a societal transition to smaller, less numerous settlements. The apparent decline fits the pattern expected as a consequence of the Maori’s overexploitation of moa. Finally, the Maori introduced the Polynesian rat and the dog to New Zealand. The actions of these potential nest predators could have reduced moa populations without leaving much direct evidence. The Maori may have also inadvertently brought pests and disease organisms in fowls, which could have crossed over to eradicate moa populations. The possibility of analyzing ancient DNA to identify past diseases of extinct animals is being explored. However, evidence of such diseases is difficult to determine directly from paleoecological or archaeological remains. For these reasons, it is hard to determine the likelihood that introduced disease organisms were a cause of the decline of moa, but they are potentially significant. While the last of these possible causes remains speculative, definite clues exist for the action of the first two causes. The story of moa species and their demise raises ecological issues on the vulnerability of species to human-caused changes—including altered vegetative cover of the landscape, change in the physical environment, and modification of the flora and fauna of a region by eliminating some species and introducing others.