求助，费费一个CR题

wanghongliang

58. Some people say that the scarcity of food is a function of the finite limits of the earth’s resources, coupled with a relentless rate of population growth. This analysis fails to recognize, however, that much of the world’s agricultural resources are used to feed livestock instead of people. In the United States, for example, almost one-half of the agricultural acreage is devoted to crops fed to livestock. A steer reduces twenty-one pounds of inexpensive grain to one pound of expensive meat. Thus, the scarcity of food is not merely a function of limited resources and population growth.


Which one of the following is an assumption that would allow the conclusion in the argument to be properly drawn?


A.People prefer eating meat to eating grain.
B.Meat is twenty-one times more expensive than grain.
C.The limits of the earth’s agricultural resources are not finite.
D.More than one-half of the agricultural acreage in the United States is devoted to drops fed to humans.
E.Growing crops for human consumption on the acreage currently devoted to crops for livestock will yield more food for more people.      


文中说食物短缺不仅仅是因为资源有限和人口过多，还有喂牲口的问题
答案给出了E选项，但是将E取非，把CROP喂给牲口不会yield more food,这不正好支持结论了吗？既food scarcity也是因为喂牲口，因为他们也不能制造更多食物。。这样理解对吗？

hjbb1027

E没错，这题的意思是说，因为大部分种的谷物都喂给家畜了，说明土地

资源的承载量并不是导致世界饥饿的原因。问建立在怎样的假设之上，E的意

思是说如果把这部分喂家畜种的粮食给人吃，而不是用来喂养家畜，就会带

来更多的食物，这肯定的作者的推论。把E取非，就是给人吃并不会带来更多

的食物，就说明了，“把谷物喂给家畜”这个原因不能为结论服务，相当于

削弱了原文论述

wanghongliang

恩恩，想明白了,thanks @