『新东方在线托福听力』为托福考生准备了ETS托福TPO/Official 69 Passage2阅读练习，TPO/Official 69 Passage2原文答案解析，TPO/Official 69 Passage2阅读原文练习音频翻译。

托福TPO/Official 69 Passage2阅读原文题目答案及解析-新东方托福官方网校手机版

太平洋占地球表面的三分之一和世界海洋面积的一半。

The Pacific Ocean accounts for one-third of Earth's surface and half of the world's ocean area.

它拥有大约25,000个岛屿，其中约7,500个是海洋岛屿，相对远离大陆海岸。

It has about 25,000 islands, of which about 7,500 are oceanic, being relatively far from a continental shore.

绝大多数太平洋岛屿诞生时没有生命：坚硬、致密的火山岩在海面上形成疙瘩。

The great majority of all Pacific islands were born barren of life: hard, dense, volcanic rock pimples on the sea's surface.

新西兰是主要例外；它是西太平洋的大陆岛屿之一，与斐济、所罗门群岛及西部的其他岛屿同属一类。

New Zealand is the chief exception; it is among the continental islands of the western Pacific, together with Fiji, the Solomons, and others to the west.

生命大多通过偶然或漂流到达其他岛屿。

Life arrived on most other islands by accident or by drift.

一些植物通过空中运输到达，鸟类消化道中携带的种子占夏威夷早期植物的近40%。

Some plants arrived by air transport, seeds carried in the digestive tracts of birds account for nearly 40 percent of Hawaii’s early plants.

首批入侵者要么是能在空气或水中漂浮得足够好以跨越海洋的生物，要么是种子能在鸟类肠道中存活航行的生物。

The first invaders were either creatures that could float well enough, in air or water, to cross stretches of ocean, or those whose seeds could survive a voyage in some bird's gut.

在海平面较低的时候，陆桥连接或几乎连接了西太平洋的许多岛屿，因此一些物种在无需特别擅长漂浮或偷渡的情况下殖民了这些岛屿。

At times of lower sea level, land bridges linked, or nearly linked, many islands in the far western Pacific, so some species colonized these islands without being notably good floaters or stowaways.

在东太平洋（如复活节岛），只有最擅长漂浮和旅行的物种到达并存活下来。

In the eastern Pacific (Easter Island, for example) only the best floaters and travelers arrived and survived.

因此，西部岛屿的物种数量和生物多样性远超波利尼西亚的东部岛屿。

Consequently, the western islands have far more species and far greater biodiversity than do the eastern islands of Polynesia.

哺乳动物很难在太平洋岛屿上扩散；只有蝙蝠和老鼠成功地在新几内亚以东殖民。

Mammals found it hard to get anywhere in the island Pacific; only bats and rats successfully colonized east of New Guinea.

几乎所有物种都源自亚洲；早期太平洋是一个亚洲湖泊，仅有极少比例的物种来自美洲。

Almost all species derive from Asia; the early Pacific was an Asian lake, with only a tiny proportion of species from the Americas.

根据经验，离印尼越远，植物和动物生命越贫乏，因此在面对干扰时越不稳定和缺乏恢复力。

As a rule of thumb, the further from Indonesia, the more impoverished the plant and animal life and, in consequence, the less stable and resilient in the face of disturbance.

这种衰减对陆地物种影响强烈，对海洋物种影响较弱，对海洋鸟类不存在影响，但对陆地鸟类影响相当明显。

This attenuation is strong for land species, less strong for marine species, and nonexistent for oceanic birds, although fairly strong for land birds.

太平洋生态系统在相对（但程度不同）的隔离中进化，远离大陆生物进化的熔炉。

Pacific ecosystems evolved in relative (but differential) isolation from the continental crucibles of biological evolution.

这意味着物种形成的机会：新物种发展并占据在其他地方已被填补的生态位。

This meant opportunities for speciation: the development of new species occupying ecological niches that elsewhere were already filled.

博物学家查尔斯·达尔文描述的加拉帕戈斯群岛上的雀类——这些鸟类分为不同物种，每种专为一个狭窄生态位——是经典案例。

The finches described by the naturalist Charles Darwin on the Galapagos Islands—birds that divided into different species, each specialized for a narrow niche—are the classic example.

在没有哺乳动物的岛屿上，爬行动物和鸟类取而代之。

On islands that had no mammals, reptiles and birds took their place.

因此，加拉帕戈斯有巨型乌龟，新西兰曾有功能类似浏览或放牧哺乳动物的大型鸟类。

Thus the Galapagos have giant tortoises, and New Zealand once had giant birds that functioned more or less like browsing or grazing mammals.

在太平洋大部分地区，缺乏放牧动物意味着植物没有发展出防御机制，如刺、有毒化学物质或苦味。

Throughout most of the Pacific, the paucity of grazing animals meant that plants developed no defenses, such as spines, poisonous chemicals, or bitterness.

较偏远的岛屿具有很高的特有种比例——即仅存在于那里的物种。

The remoter islands had a very high proportion of endemism—that is, of species that existed only there.

以夏威夷为例，多达99%的物种是特有的。

In the case of Hawaii, as many as 99 percent of the species were endemic.

这一切导致陆地岛屿物种在生物学上具有一定的脆弱性，如果它们必须与大陆上更激烈生存竞争的获胜者争夺生态位空间。

All this led to a certain biological vulnerability among the terrestrial island species, should they ever be obliged to compete for niche space with the winners of the more intense continental competitions for survival.

这种脆弱性向东和向太平洋更偏远的角落增加，沿主要由隔离程度定义的梯度变化。

This vulnerability increased toward the east and toward the remoter corners of the Pacific along a gradient defined chiefly by the degree of isolation.

第二个可能更决定性的脆弱性来源，源于人类在太平洋的到来。

A second source of vulnerability, perhaps more decisive, arose from the arrival of humankind in the Pacific.

岛屿动物在进化过程中没有经历过人类的方式，或者任何大型陆地捕食者的影响。

Island animals evolved with no experience of the ways of humankind, or indeed of any large terrestrial predators.

因此，它们对捕食者或人类行为的影响没有免疫力。

As a result, they had no immunities to predators or the effects of human action.

太平洋动物往往缺乏警惕，容易成为猎物。

Pacific animals were often unwary and easy prey.

在极端情况下，如加拉帕戈斯，达尔文发现许多鸟类几乎是驯服的，天真地信任到允许他靠近到手臂可及的距离。

At the extreme, again the Galapagos, Darwin found many birds almost tame, so naively trusting that they would allow him to get within arm's reach.

太平洋植物对火的经验很少，因为自然火灾极为罕见，除了少数地方。

Pacific plants had little experience with fire, because natural fires were very rare, except in a few places.

因此，很少有植物能很好地适应火，大多数植物对火显得脆弱。

Thus few plants were well adapted to fire, and most proved vulnerable to it.

相比之下，在人类存在或自然火灾更常见的地方进化的大陆物种，在火灾后能轻易恢复，有些甚至因火灾而蓬勃发展。

In contrast, continental species that had evolved in the presence of humankind, or in places where natural fire is much more common, could recover easily after burns, and some could flourish as a result of fire.

简言之，由于隔离，太平洋生态系统与大陆生态系统不同。

In short, Pacific ecosystems were different from continental ones on account of their isolation.

它们很好地适应了其环境，但对外来入侵和人类影响非常脆弱。

They were well adapted to their circumstances but very vulnerable to alien invasion and human impact.

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.

What can be inferred from the discussion about "bats" and "rats" in relation to other mammals?

According to paragraph 2, why were mammals not common in the island Pacific?

The author mentions "giant tortoises" and "giant birds" in paragraph 3 in order to

Which of the following can be inferred from paragraph 3 about why plants in Pacific ecosystems did not develop defenses?

The word "tame" in the passage is closest in meaning to

In paragraph 4, the author mentions fire in relation to plants in order to make which of the following points?

Look at the four squares  that indicate where the following sentence could be added to the passage. For example, before European impact, the western island of Bougainville in the Solomonshad several thousand plant species, while Easter Island had only 30.  Where would the sentence best fit? Click on a squareto 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.

Pacific Ecosystems The Pacific Ocean accounts for one-third of Earth's surface and half of the world's ocean area. It has about 25,000 islands, of which about 7,500 are oceanic, being relatively far from a continental shore. The great majority of all Pacific islands were born barren of life: hard, dense, volcanic rock pimples on the sea's surface. New Zealand is the chief exception; it is among the continental islands of the western Pacific, together with Fiji, the Solomons, and others to the west. Life arrived on most other islands by accident or by drift. Some plants arrived by air transport, seeds carried in the digestive tracts of birds account for nearly 40 percent of Hawaii’s early plants. The first invaders were either creatures that could float well enough, in air or water, to cross stretches of ocean, or those whose seeds could survive a voyage in some bird's gut.At times of lower sea level, land bridges linked, or nearly linked, many islands in the far western Pacific, so some species colonized these islands without being notably good floaters or stowaways. In the eastern Pacific (Easter Island, for example) only the best floaters and travelers arrived and survived. Consequently, the western islands have far more species and far greater biodiversity than do the eastern islands of Polynesia. Mammals found it hard to get anywhere in the island Pacific; only bats and rats successfully colonized east of New Guinea. Almost all species derive from Asia; the early Pacific was an Asian lake, with only a tiny proportion of species from the Americas. As a rule of thumb, the further from Indonesia, the more impoverished the plant and animal life and, in consequence, the less stable and resilient in the face of disturbance. This attenuation is strong for land species, less strong for marine species, and nonexistent for oceanic birds, although fairly strong for land birds. Pacific ecosystems evolved in relative (but differential) isolation from the continental crucibles of biological evolution. This meant opportunities for speciation: the development of new species occupying ecological niches that elsewhere were already filled. The finches described by the naturalist Charles Darwin on the Galapagos Islands—birds that divided into different species, each specialized for a narrow niche—are the classic example. On islands that had no mammals, reptile sand birds took their place. Thus the Galapagos have giant tortoises, and New Zealand once had giant birds that functioned more or less like browsing or grazing mammals. Throughout most of the Pacific, the paucity of grazing animals meant that plants developed no defenses, such as spines, poisonous chemicals, or bitterness. The remoter islands had a very high proportion of endemism—that is, of species that existed only there. In the case of Hawaii, as many as 99 percent of the species were endemic. All this led to a certain biological vulnerability among the terrestrial island species, should they ever be obliged to compete for niche space with the winners of the more intense continental competitions for survival. This vulnerability increased toward the east and toward the remoter corners of the Pacific along a gradient defined chiefly by the degree of isolation. A second source of vulnerability, perhaps more decisive, arose from the arrival of humankind in the Pacific. Island animals evolved with no experience of the ways of humankind, or indeed of any large terrestrial predators. As a result, they had no immunities to predators or the effects of human action. Pacific animals were often unwary and easy prey. At the extreme, again the Galapagos, Darwin found many birds almost tame, so naively trusting that they would allow him to get within arm's reach. Pacific plants had little experience with fire, because natural fires were very rare, except in a few places. Thus few plants were well adapted to fire, and most proved vulnerable to it. In contrast, continental species that had evolved in the presence of humankind, or in places where natural fire is much more common, could recover easily after burns, and some could flourish as a result of fire. In short, Pacific ecosystems were different from continental ones on account of their isolation. They were well adapted to their circumstances but very vulnerable to alien invasion and human impact.