『新东方在线托福阅读』为托福考生准备了ETS托福TPO/Official 38 Passage 2阅读练习：According to paragraph 3, the introduction of raccoons into Utah’s Great Salt Lake Valley appears to have been an example of an introduction that was真题题目及答案解析，TPO/Official 38 Passage 2阅读原文范文音频翻译

托福TPO/Official 38 Passage 2阅读原文According to paragraph 3, the introduction of raccoons into Utah’s Great Salt Lake Valley appears to have been an example of an introduction that was题目答案及解析-新东方托福官方网校手机版

浣熊的分布之广横跨北美洲和中美洲的大部分地区。

Raccoons have a vast transcontinental distribution, occurring throughout most of North America and Central America.

从加拿大南部一直到巴拿马，以及沿海地区的岛屿上，都能找到浣熊的身影。

They are found from southern Canada all the way to Panama, as well as on islands near coastal areas.

They occur in each of the 49 states of the continental United States.

尽管浣熊仅仅源于西半球，但它们成功地迁移到了世界其他地区。

Although raccoons are native only to the Western Hemisphere, they have been successfully transplanted to other parts of the globe.

浣熊的数量在二十世纪三十年代下降到了一个相对较低的水平，但从1943年的繁殖季节开始，它们的数量开始逐渐增长。

Following a decline to a relatively low population level in the 1930s, raccoons began to prosper following their 1943 breeding season.

整个二十世纪四十年代，它们的数量持续激增，从那时起一直到现在数量都维持在高位。

A rapid population surge continued throughout the 1940s, and high numbers have been sustained ever since.

到二十世纪八十年代末，人们估计浣熊在北美的数量至少是二十世纪三十年代时数量的15到20倍。

By the late 1980s, the number of raccoons in North America was estimated to be at least 15 to 20 times the number that existed during the 1930s.

到目前为止，它们的数量毋庸置疑变得更多了，因为浣熊继续开拓新的领地，而这些栖息地正是此前少有或者没有浣熊的地方，例如沙地草原、沙漠、沿海湿地以及山区。

By now, their numbers have undoubtedly grown even more, as they have continued to expand into new habitats where they were once either rare or absent, such as sandy prairies, deserts, coastal marshes, and mountains.

它们遍布落基山脉西部这一现象足以表明它们有能力快速开拓新环境。

Their spread throughout the Rocky Mountain West is indicative of the fast pace at which they can exploit new environments.

尽管有不少浣熊会被捕获，偶尔也会由于疾病而遭受数量上的下滑，但它们的总数始终保持在较高水平。

Despite significant numbers being harvested and having suffered occasional declines, typically because of disease, the raccoon has consistently maintained high population levels.

有一些因素可以解释浣熊在数量和分布上的急剧增长。

Several factors explain the raccoon’s dramatic increase in abundance and distribution.

首先，由于浣熊常常生活在郊区甚至城市环境中，它们成功的部分原因要归因于城市的发展。

First, their success has been partially attributed to the growth of cities, as they often thrive in suburban and even urban settings.

此外，人们还有意把浣熊引入到美洲大陆的各地。

Furthermore, they have been deliberately introduced throughout the continent.

在美国境内，无论合法与否，人们通常会把浣熊从一个地区带到另一个地区，它们被用来补充狩猎区，或者仅仅可能是由于人们希望浣熊融入当地的动物群。

Within the United States, they are commonly taken from one area to another, both legally and illegally, to restock hunting areas and, presumably, because people simply want them to be part of their local fauna.

在过去40年间，看上去正是这种引入方式使得浣熊出现在犹他州的大盐湖流域并在此发展壮大。

Their appearance and subsequent flourishing in Utah’s Great Salt Lake valley within the last 40 years appears to be from such an introduction.

一个很好的引入成功的例子就是来自（美国中西部）印第安纳州的浣熊能够在阿拉斯加沿海小岛上繁衍生息。

As an example of the ease with which transplanted individuals can succeed, raccoons from Indiana (midwestern United States) have reportedly been able to flourish on islands off the coast of Alaska.

农业的发展或许也是浣熊在不同地区扩张的一个原因。

The raccoon’s expansion in various areas may also be due to the spread of agriculture.

浣熊会采食农作物，尤其是玉米和谷粒都已成为它们可靠的食物来源。

Raccoons have been able to exploit crops, especially corn but also cereal grains, which have become dependable food sources for them.

然而农业的扩张未必会导致浣熊数量的快速增长。

The expansion of agriculture, however, does not necessarily lead to rapid increases in their abundance.

（位于美国中西部地区的）堪萨斯州和科罗拉多州东部的农业于十九世纪七、八十年代取得了快速发展，但是直到大约50年后浣熊才从它们的主要栖息地——树木繁茂的河边低地逐渐扩展到这些农业地区。

Farming in Kansas and eastern Colorado (central and western United States) proceeded rapidly in the 1870s and 1880s, but this was about 50 years before raccoons started to spread out from their major habitat, the wooded river bottomlands.

它们同样扩张到了像牧场这样没有其他农业生产的地区，以及没有森林或常流河的地方。

They have also expanded into many areas lacking any agriculture other than grazing and into places without forests or permanent streams.

早在欧洲人在北美大平原地区（从加拿大中部以南涵盖美国中西部一直到德州的一片辽阔的草原地带）定居并农耕之前，人们或许只能在河流和溪流沿岸以及该地区东南部的林地中发现浣熊的身影。

Prior to Europeans settling and farming the Great Plains region, a vast grassland region in North America extending from central Canada south through the west central United States into Texas, raccoons probably were just found along its rivers and streams and in the wooded areas of its southeastern section.

除了曼尼托巴省南部地区以外，在加拿大其他地区都很难找到浣熊的踪影。

With the possible exception of the southern part of the province of Manitoba, their absence was notable throughout Canada.

它们最初在曼尼托巴省南部分布比较广泛，到了二十世纪四十年代浣熊的数量在该省的东南部也相当可观。

They first became more widely distributed in the southern part of Manitoba, and by the 1940s were abundant throughout its southeastern portion.

在二十世纪五十年代，浣熊群体在加拿大快速增长。

In the 1950s their population swelled in Canada.

二十世纪五十年代在大草原地区对丛林狼的控制可能是浣熊扩张的一个因素。

The control of coyotes in the prairie region in the 1950s may have been a factor in raccoon expansion.

如果数量充足的话，丛林狼或许有能力来抑制浣熊的数量（尽管这一观点缺乏直接证据的支撑）。

If their numbers are sufficient, coyotes might be able to suppress raccoon populations (though little direct evidence supports this notion).

到二十世纪六十年代，筑巢于马尼托巴省西南部的帆背潜鸭成为了浣熊的主要猎物。

By the 1960s the raccoon had become a major predator of the canvasback ducks nesting in southwestern Manitoba.

狼在邻国美国大部分地区的灭绝或许是导致浣熊扩张和数量增长的一个关键因素。

The extermination of the wolf from most of the contiguous United States may have been a critical factor in the raccoon’s expansion and numerical increase.

在十八世纪，当狼的活动范围遍及几乎整个北美大陆时，很明显浣熊仅仅在东部落叶林、墨西哥湾沿岸以及五大湖区中大量存在，尽管它们也扩展到了美国中西部地区主要河流的树木繁茂的洼地。

In the eighteenth century, when the wolf’s range included almost all of North America, raccoons apparently were abundant only in the deciduous forests of the East, Gulf Coast, and Great Lakes regions, though they also extended into the wooded bottomlands of the Midwest’s major rivers.

在这些地区，在树上栖息的习惯以及中空树洞的存在为浣熊躲避狼和其他大型捕食者提供了一些保护。

In such areas, their arboreal habits and the presence of hollow den trees should have offered some protection from wolves and other large predators.

即使浣熊并不是这些捕食者的主要猎物，但当浣熊暴露在相对缺少树木的地区时，狼肯定会试图捕食浣熊。

Even though raccoons may not have been a significant part of their diet, wolves surely would have tried to prey on those exposed in relatively treeless areas.

According to paragraph 2, what happened to raccoons in the 1930s?

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.

According to paragraph 3, the introduction of raccoons into Utah’s Great Salt Lake Valley appears to have been an example of an introduction that was

All of the following are mentioned in paragraph 3 as helping to explain the raccoon’s dramatic increase in abundance and distribution EXCEPT:

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

According to paragraph 4, how has the spread of agriculture affected raccoon populations?

What can be concluded from the discussion in paragraph 5 about coyotes and raccoons in Manitoba?

According to paragraph 6, during the eighteenth century, raccoons were abundant only in forests and wooded bottomlands of major rivers mainly because those were the only places where raccoons

Look at the four squares  that indicate where the following sentence could be added to the passage. Indeed, raccoons now occur in many parts of Europe and Asia, far outside their natural range.  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 Racoon's Success Raccoons have a vast transcontinental distribution, occurring throughout most of North America and Central America.  They are found from southern Canada all the way to Panama, as well as on islands near coastal areas.  They occur in each of the 49 states of the continental United States.  Although raccoons are native only to the Western Hemisphere, they have been successfully transplanted to other parts of the globe.  Following a decline to a relatively low population level in the 1930s, raccoons began to prosper following their 1943 breeding season. A rapid population surge continued throughout the 1940s, and high numbers have been sustained ever since. By the late 1980s, the number of raccoons in North America was estimated to be at least 15 to 20 times the number that existed during the 1930s. By now, their numbers have undoubtedly grown even more, as they have continued to expand into new habitats where they were once either rare or absent, such as sandy prairies, deserts, coastal marshes, and mountains. Their spread throughout the Rocky Mountain West is indicative of the fast pace at which they can exploit new environments. Despite significant numbers being harvested and having suffered occasional declines, typically because of disease, the raccoon has consistently maintained high population levels. Several factors explain the raccoon’s dramatic increase in abundance and distribution. First, their success has been partially attributed to the growth of cities, as they often thrive in suburban and even urban settings. Furthermore, they have been deliberately introduced throughout the continent. Within the United States, they are commonly taken from one area to another, both legally and illegally, to restock hunting areas and, presumably, because people simply want them to be part of their local fauna. Their appearance and subsequent flourishing in Utah’s Great Salt Lake valley within the last 40 years appears to be from such an introduction. As an example of the ease with which transplanted individuals can succeed, raccoons from Indiana (midwestern United States) have reportedly been able to flourish on islands off the coast of Alaska. The raccoon’s expansion in various areas may also be due to the spread of agriculture. Raccoons have been able to exploit crops, especially corn but also cereal grains, which have become dependable food sources for them. The expansion of agriculture, however, does not necessarily lead to rapid increases in their abundance. Farming in Kansas and eastern Colorado (central and western United States) proceeded rapidly in the 1870s and 1880s, but this was about 50 years before raccoons started to spread out from their major habitat, the wooded river bottomlands. They have also expanded into many areas lacking any agriculture other than grazing and into places without forests or permanent streams. Prior to Europeans settling and farming the Great Plains region, a vast grassland region in North America extending from central Canada south through the west central United States into Texas, raccoons probably were just found along its rivers and streams and in the wooded areas of its southeastern section. With the possible exception of the southern part of the province of Manitoba, their absence was notable throughout Canada. They first became more widely distributed in the southern part of Manitoba, and by the 1940s were abundant throughout its southeastern portion. In the 1950s their population swelled in Canada. The control of coyotes in the prairie region in the 1950s may have been a factor in raccoon expansion. If their numbers are sufficient, coyotes might be able to suppress raccoon populations (though little direct evidence supports this notion). By the 1960s the raccoon had become a major predator of the canvasback ducks nesting in southwestern Manitoba. The extermination of the wolf from most of the contiguous United States may have been a critical factor in the raccoon’s expansion and numerical increase. In the eighteenth century, when the wolf’s range included almost all of North America, raccoons apparently were abundant only in the deciduous forests of the East, Gulf Coast, and Great Lakes regions, though they also extended into the wooded bottomlands of the Midwest’s major rivers. In such areas, their arboreal habits and the presence of hollow den trees should have offered some protection from wolves and other large predators. Even though raccoons may not have been a significant part of their diet, wolves surely would have tried to prey on those exposed in relatively treeless areas.