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题库 / OG2016-CR-94
Last year a global disturbance of weather patterns disrupted harvests in many of the world's important agricultural areas. Worldwide production of soybeans, an important source of protein for people and livestock alike, was not adversely affected, however. Indeed, last year's soybean crop was actually slightly larger than average. Nevertheless, the weather phenomenon is probably responsible for a recent increase in the world price of soybeans.
Which of the following, if true, provides the strongest justification for the attribution of the increase in soybean prices to the weather phenomenon?
Last year's harvest of anchovies, which provide an important protein source for livestock, was disrupted by the effects of the weather phenomenon.
Most countries that produce soybeans for export had above-average harvests of a number of food crops other than soybeans last year.
The world price of soybeans also rose several years ago, immediately after an earlier occurrence of a similar global weather disturbance.
Heavy rains attributable to the weather phenomenon improved grazing pastures last year, allowing farmers in many parts of the world to reduce their dependence on supplemental feed.
Prior to last year, soybean prices had been falling for several years.
情景：去年一个全球性的天气模式干扰破坏了很多世界重要的农业区。但是，大豆并没有被影响。实际上，大豆的产量反而还上升了一些。天气现反而还帮助了大豆的价格上升。
推理：由于推理文段没有结论，所以为演绎推理。问题是要我们找到“天气现反而还帮助了大豆的价格上升”的原因。
选题方式：略
选项分析：
A选项：Correct. 凤尾鱼是一个给家畜提供蛋白质的东西，去年凤尾鱼的收成由于天气的原因而下降了。如果凤尾鱼的数量下降，那么为了让人类和家畜吃到足够量的蛋白质，人们就必须购买大豆了。
B选项：很多生产大豆的国家生产其它种类的庄稼量也上升了。本选项和要解释的现象无关。
C选项：在一些年以前，大豆的价格也在类似的天气条件出现后上升了。以前出现过，不代表这次依然会出现，自然也不能解释这次的出现。
D选项：大雨在去年提升了放牧的草场，这让农民们不用再去额外的补给食物了。本选项和要解释的现象无关。
E选项：在去年以前，大豆的价格已经降了好几年了。过去的增减均不能解释现在的变化。
看到很多朋友也和我曾经一样错选C，想明白了给大家解释一下。1.为什么Nevertheless,...不是结论：因为结论需要前提去back up，这句话前面没有任何前提，只是说大豆的“产量”在极端天气不增反降，和大豆的”价格“并没关系。2.为什么不是相关因果型：题目有提到一对相关性：极端天气和大豆”产量“不受影响；结论的相关性是极端天气和大豆”价格“上升。大豆产量和价格是不能直接替换的，至少不能不加解释就替换掉。（而且这里大豆产量上升了，按照经济学常识大豆价格应该下降，和题目给的情形矛盾了，更不能把大豆产量和价格直接替换了）总结：注意题目中具体讨论的重心是什么，不要看到soybean什么就当作一回事。
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