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标题: 有一道题求解答，感觉用了方法反而做错 [打印本页]

作者: 467582826 时间: 2018-4-20 23:11
标题: 有一道题求解答，感觉用了方法反而做错
PREP 07 PART1-CR-22
In the late 1980s, the population of sea otters in the North Pacific began to decline. There are two plausible explanations for the decline: predation, possibly by killer whales, or disease. Of these two, disease is the more likely, since a concurrent sharp decline in populations of seals and sea lions is believed to have been caused by disease, and diseases that infect these creatures are likely to be able to infect sea otters also.
Which of the following, if true, most seriously weakens the reasoning?
A Killer whales in the North Pacific usually prey on seals and sea lions but will, when this food source is scarce, seek out other prey.
B There is no indication that the sea otter population at any North Pacific location declined in the 1980s because of substantial numbers of sea otters migrating to other locations.
C Along the Pacific coast of North America in the 1980s, sea otters were absent from many locations where they had been relatively common in former times.
D Following the decline in the population of the sea otters, there was an increase in the population of sea urchins, which are sea otters' main food source.
E The North Pacific populations of seals and sea lions cover a wider geographic area than does the population of sea otters.

答案应该是A。

最初做题时，我认为这是类比推理，前提：海豹和海狮死亡是因为生病；结论：水懒死亡也是因为生病。用类比的方法，那就是找二者之间的不同，我就选了E。

如果不用这个方法，我应该就选A了，所以不知道到底哪里有问题，求指教

作者: liwenwhpu 时间: 2018-4-23 06:41
文中说sea otters数量下降有两种解释。一种是killer whales,一种是疾病。作者认为是疾病引起的下降，因为seals 和sea lions 也数量也下降了。
A说的是killer whales 在食物缺乏时，会吃其他猎物（暗指sea otters）。所以这个解释削弱了作者观点--sea otters数量下降是由疾病造成的。

作者: cycgundam 时间: 2018-5-7 07:44
所谓的不同，应该是就逻辑的联系而言。

我知道楼主看到两者的生存范围大小不同，故而认定该不同具有削弱作用？其实这个不同，必须要对命题的逻辑有影响。

如果E的选项是The North Pacific populations of seals and sea lions cover a geographic area where sea otters don't populate. 那应该就很接近正确选项了。如果是只是单单生存范围大小不同，如果生存空间彼此有交集，两个物种有机会接触互相传染病毒，那不就对命题产生support作用了么？所以生存范围大小并不一定具有削弱作用，可以说一定程度上它是无关选项。

A选项的优越性在于提供了一个Alternative。虽然A选项并没有将这个Alternative说的非常明显。

作者: 467582826 时间: 2018-5-7 09:37

cycgundam 发表于 2018-5-7 07:44
所谓的不同，应该是就逻辑的联系而言。

我知道楼主看到两者的生存范围大小不同，故而认定该不同具有削弱作 ...

嗯嗯，谢谢，其实后来想想，是我刚用这个方法，非把自己圈在里面，一定要去较真，结果还较不对

作者: 467582826 时间: 2018-5-7 09:44

liwenwhpu 发表于 2018-4-23 06:41
文中说sea otters数量下降有两种解释。一种是killer whales,一种是疾病。作者认为是疾病引起的下降，因为se ...

好的，懂啦，谢谢~

作者: liuyongxue 时间: 2019-6-26 11:48
其实最重要的还是理解题目在讲一个什么样的故事，看懂了最重要

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