[讨论][求助]请教2道og 题!

fernandochang

其实是1个题组啦!   但是依然不懂!!!!!  求教!

Questions 138-139 are based on the following.
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.

138. Sharon's argument is structured to lead to which of the following as a conclusion?
(A) The fact that 90% of the people know someone who is unemployed is not an indication that unemployment is abnormally high.
(B) The current level of unemployment is not moderate.
(C) If at least 5% of workers are unemployed, the result of questioning a representative group of people cannot be the percentage Roland cites.
(D) It is unlikely that the people whose statements Roland cites are giving accurate reports.
(E) If an unemployment figure is given as a certain percent, the actual percentage of those without jobs is even higher.
A): A  

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
(D) knowledge that a personal acquaintance is unemployed generates more fear of losing one's job than does
   knowledge of unemployment statistics
A):B