~求助~~~旧PREP1 逻辑Q58 求NN们解释。。。。。。

fangzikai

58.(34705-!-item-!-188;#058&007581)

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.

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

看了07逻辑笔记。一开始选的A。 后来看解释觉得B也对。。但是还是不明白A为什么错。。他的结论不就是建立在这个失业率是不变的条件下的么。A中rarely exceeded不就是失业率比较稳定。。不明白为什么A不好。求各种NN们解释

kidvii

但是他没有说rarely。只是说，R给的证据不能说明。

fangzikai

谢谢回复。可是5%的失业率是稳定不变的才可以呀。。A不是这个意思?我理解错了？

fangzikai

没人落落呀 自己顶一下吧还是

sdcar2010

Whether or not "normal levels of unemployment are rarely exceeded" has no bearing on the conclusion in the passage. Thus it is not the necessary assumption we are looking for.

fangzikai

好吧 可是我想多了 总是偏离文章主题 苦恼

sdcar2010

Roland hints that the unemployment rate is high since 90% people know someone is unemployed.

Sharon disagrees and claims it is normal for 90% people to know someone who is umemployed at a normal umemployment rate of 5%.

For necessary assumption questions, just use negation and see if that would cause the arugment to cumble.  If so, that answer choice is correct.  You do not need to worry why other choices are not assumptions other than that those wrong choices have no impact on the argument.

Let's negate B:
Unemployment is normally concentrated in geographically isolated segments of the population.

If this is true, then certain area will have extremely high unemployment rate (let's say 10.5%) while other areas will have extremely low unemployment rate (let's say it is 0.5%). The national average for unemployment is still 5%. Then in the area with low unemployment, every 200 people will have one unemployed.  Then if one knows 50 people, it is likely that none of these 50 people are unemployed. Sharon's argument falls apart.

fangzikai

谢谢楼上的解释 很详细 我明白了

kevingod

我这样解释看看对不对。Sharon这段有两句话：第一句But...是前提，第二句so...是结论。假设题型假设的位置应该介于前提和结论之间，充当bridge的作用，A选项把假设放在前提中，所以是错的。

jessi4765

好厉害啊！看过你的好多逻辑解释，很佩服啊！