大全-8-13

mudiduanger

请教一道逻辑大全第8套的13题：
The program to control the entry of illegal drugs into the country was a failure in 1987. If the program had been successful, the wholesale price of most illegal drugs would not have dropped substantially in 1987.



13.
The argument in the passage depends on which of the following assumptions?



(A) The supply of illegal drugs dropped substantially in 1987.



(B) The price paid for most illegal drugs by the average consumer did not drop substantially in 1987.



(C) Domestic production of illegal drugs increased at a higher rate than did the entry of such drugs into the country.

(D) The wholesale price of a few illegal drugs increased substantially in 1987.

(E) A drop in demand for most illegal drugs in 1987 was not the sole cause of the drop in their wholesale price.




答案选的是E.
我想问一下为什么B不对呢？如果人均消费价格大幅度下跌的话也有可能wholesale price会大幅度下降啊～
前提不就是把其他可能导致的原因去除吗？

banglixing

这个提干是因果还是条件？因为wholesale price drop所以 a failure吗？

fangzep

" If the program had been successful, the wholesale price of most illegal drugs would not have dropped substantially in 1987."
可推出program成功的必要条件是price of most illegal drugs 不下降。必要条件不一定是program成功的充分条件，因为充分条件可能有多个。选项E符合。

daoyinger

原文：1987年一项阻止非法药品进入的项目失败了。如果成功，则在该年非法药品的价格将不会出现实质性降价。
问题：隐含的假设是什么？
分析：题干的逻辑是：如果成功，则进入的非法药品将实质减少，非法药品实质减少了，则非法药品的价格将不会出现实质降低。
隐含的假设是：药品的供应量与价格存在实质性的联系。即药品供应量减少必然导致非法药品的价格不会实质降低，即使非法药品的消费量同时出现一定幅度的减少。因此，作者的潜台词表明非法药品的价格并非受药品消费量一个因素决定。对E取非更好理解。