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[Reading Comprehension]
试题详情
文章：
| Line | There are recent reports of apparently drastic |
| declines in amphibian populations and of extinctions | |
| of a number of the world’s endangered amphibian | |
| species. These declines, if real, may be signs of a | |
| (5) | general trend toward extinction, and many |
| environmentalists have claimed that immediate | |
| environmental action is necessary to remedy | |
| this “amphibian crisis,” which, in their view, is an | |
| indicator of general and catastrophic environmental | |
| (10) | degradation due to human activity. |
| To evaluate these claims, it is useful to make a | |
| preliminary distinction that is far too often ignored. | |
| A declining population should not be confused with | |
| an endangered one. An endangered population is | |
| (15) | always rare, almost always small, and, by definition, |
| under constant threat of extinction even without a | |
| proximate cause in human activities. Its disappearance, | |
| however unfortunate, should come as no great | |
| surprise. Moreover, chance events—which may | |
| (20) | indicate nothing about the direction of trends in |
| population size—may lead to its extinction. The | |
| probability of extinction due to such random factors | |
| depends on the population size and is independent of | |
| the prevailing direction of change in that size. | |
| (25) | For biologists, population declines are potentially |
| more worrisome than extinctions. Persistent | |
| declines, especially in large populations, indicate a | |
| changed ecological context. Even here, distinctions | |
| must again be made among declines that are only | |
| (30) | apparent (in the sense that they are part of habitual |
| cycles or of normal fluctuations), declines that take | |
| a population to some lower but still acceptable | |
| level, and those that threaten extinction (e.g., by | |
| taking the number of individuals below the minimum | |
| (35) | viable population). Anecdotal reports of population |
| decreases cannot distinguish among these | |
| possibilities, and some amphibian populations have | |
| shown strong fluctuations in the past. | |
| It is indisputably true that there is simply not | |
| (40) | enough long-term scientific data on amphibian |
| populations to enable researchers to identify real | |
| declines in amphibian populations. Many fairly | |
| common amphibian species declared all but extinct | |
| after severe declines in the 1950s and 1960s | |
| (45) | have subsequently recovered, and so might |
| the apparently declining populations that have | |
| generated the current appearance of an amphibian | |
| crisis. Unfortunately, long-term data will not soon | |
| be forthcoming, and postponing environmental | |
| (50) | action while we wait for it may doom species and |
| whole ecosystems to extinction. |
题目：
The primary purpose of the passage is to
选项:
A、assess the validity of a certain view
B、distinguish between two phenomena
C、identify the causes of a problem
D、describe a disturbing trend
E、allay concern about a particular phenomenon
答案:
A
提问：
请问老师可以大概讲一下这篇文章的思路吗，我对文章的大概理解是这样：环境学家认为两栖动物减少和灭绝是因为人为活动，作者评估了这个想法，否认了这个观点，发现可能还有别的影响因素，并且研究两栖动物减少这一事件还缺乏足够的数据支撑。（其实我第三第四段思路有点混乱）另外我这道题选的是E，我觉得文章是讨论了两栖动物减少和灭绝这一现象及原因，让人们关注到这一现象。可以讲下我思路错在哪吗，谢谢！
解答：
点赞1
阅读463
提问：
请问老师可以大概讲一下这篇文章的思路吗，我对文章的大概理解是这样：环境学家认为两栖动物减少和灭绝是因为人为活动，作者评估了这个想法，否认了这个观点，发现可能还有别的影响因素，并且研究两栖动物减少这一事件还缺乏足够的数据支撑。（其实我第三第四段思路有点混乱）另外我这道题选的是E，我觉得文章是讨论了两栖动物减少和灭绝这一现象及原因，让人们关注到这一现象。可以讲下我思路错在哪吗，谢谢！
解答：
点赞1
阅读464
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