OG-139请教

davidcopper

Roland: The alarming fact is that 90 percent of the people in this country now report that they
know someone who is unemployed.
Sharon: But a normal, moderate level of unemployment is 5 percent, with 1 out of 20 workers
unemployed. So at any given time if a person knows approximately 50 workers, 1 or more will
very likely be unemployed.

139. Sharon's argument relies on the assumption that
(A) normal levels of unemployment are rarely exceeded

(B) unemployment is not normally concentrated in geographically isolated segments of the
population
(C) the number of people who each know someone who is unemployed is always higher
than 90% of the population
(D) Roland is not consciously distorting the statistics he presents
(E) knowledge that a personal acquaintance is unemployed generates more fear of losing
one's job than does knowledge of unemployment statistics

答案是B,我的理解是Sharon的论点基于这样的assumption-----失业问题不是仅仅孤立地集中在失业人口上(还要看失业比例).  不知道这样理解对吗?

感觉很绕弯弯,我觉得得出结论的假设应该主要基于"if a person knows approximately 50 workers"

chwayne

看一下OG对B的解释，很清楚的。正常情况是5％（1/20)，可结论是1/50，怎么得出的呢，因为有个必要条件（NC）：unemployment is not normally concentrated in geographically isolated segments of the population。推理过程就是：5％＋B得出1/50，假设是B。

davidcopper

楼上的解释值得商榷,我想结论是"90%的人认识失业者很正常",而不是1/50

因为正常情况下每20个人就有一个失业的,只要你认识的人多于20,就可能包括失业的

又体会了一下题目, 觉得是基于这样的assumption, 即从总的失业率推理问题,而不是关注某些地区的状况(因为各地失业率高低不同),这样解释就好理解多了,也是OG的原意吧.

swlfx

答案比较饶口.不过觉得3楼的理解更加顺畅一些.谢谢.

v22

这道题目3楼说的好，但是有一点还没想通：推理过程就是：5％＋B得出1/50

5%+B=1/50？？？但是B没有任何数据显示啊，怎么得出这个公式？

就块考，实在被卡了，救命11

v22

匝呢？