[请教]陈向东逻辑假设 习题第47

shanexwang

Exports of United Stateswood pulp will rise considerably during this year. The reason for the rise is that the falling value of the dollar will make it cheaper for paper manufacturers in Japan and Western Europe to buy American wood pulp than to get it from any other source.
Which of the following is an assumption made in drawing the conclusion above?

A.Factory output of paper products in Japan and
Western Europe will increase sharply during this year.

B.The quality of the wood pulp produced in the United States
would be adequate for the purposes of Japanese and Western European paper manufacturers.

C.Paper manufacturers in Japan and Western Europe would prefer to use wood pulp produced in the
United States if cost were not a factor.

D.Demand for paper products made in Japan and
Western Europe will not increase sharply during this year.

E.Production of wood pulp by United States
companies will not increase sharply during this year.

为何C不对呢？ C 不是题中论证的逆否命题吗？

nesstang

选B？

shanexwang

是啊，但是为什么C不对呢？因为重复了题目结论吗？

nesstang

我觉得应该选最优选项

C选项直说了 生产商的偏好，不确定性太大

echodancing

在B和C两个之间犹豫了很久，查了别的论坛说的话。研究了C很久，终于领悟为啥选B。个人觉得这道题目出得不是很好，不像Gmat的风格，anyway，还是来看看吧。
这是国外论坛上面一个人的回复
(C) Paper manufacturers in Japan and Western Europe would NOTprefer to use wood pulp produced in the United States if cost were not a factor.
Well, okay. They wouldn't want to use U.S. wood pulp if cost weren't a factor; however, this argument says that cost is a factor. It is cheaper for the foreign countries to use U.S. wood pulp because the dollar is falling. In fact, the argument uses cost as a premise for why the U.S. export of wood pulp will rise. Thus, cost IS a factor. What they would prefer otherwise is irrelevant to this situation, and thus this answer does not destroy our conclusion.

简单来说，C说的是，如果不考虑价格，那么这两个国家会选择美国的货物。这是在不考虑价格的情况下，那么如果考虑起价格呢？那么这事就不好说了。虽然题目说这个货物便宜了哦，比别的地方买都要便宜哦，但是这是否就能绝对推出“这两个国家肯定会买这东西”的结论呢？不可以，没有更多的信息我们没法下这个结论，有可能货物单价便宜，但是加上运费会贵，你没法肯定下结论。
所以还是应该从B的角度来说，要货能用才行，货都不能用价格算个毛……
anyway，还是觉得这道题目出得不好，但是从某一方面可以吸取一个教训，要注意这种题干里面的词，如果表明说了价格不是factor，而题目却说价格是factor，那么就可以排除了，两者的情况都不一样哦。

shanexwang

明白了，谢谢各位~