大全-B-19

dally

19.   The U.S. census is not perfect: thousands of Americans probably go uncounted. However, the basic statistical portrait of the nation painted by the census is accurate. Certainly some of the poor go uncounted, particularly the homeless; but some of the rich go uncounted as well, because they are often abroad or traveling between one residence and another.

Which of the following is an assumption on which the argument above depends?

(A) Both the rich and the poor have personal and economic reasons to avoid being counted by the census.

(B) All Americans may reasonably be classified as either poor or rich.

(C) The percentage of poor Americans uncounted by the census is close to the percentage of rich Americans uncounted.

(D) The number of homeless Americans is approximately equal to the number of rich Americans.

(E) The primary purpose of the census is to analyze the economic status of the American population.

答案选C，我搞不清楚唉。哪位大侠给讲讲。C和D讲的不是一回事吗？

mariezhu

C讲的是未被统计的穷人的比例和未被统计的富人的比例

而D讲的是homeless的人数和富人的人数

首先根据Certainly some of the poor go uncounted, particularly the homeless这句话，穷人不仅限于homeless，也许还有别人；

其次如果象D那样仅是人数相同，那么基数如果不同，会使比例不同，不能达到the basic statistical portrait of the nation painted by the census is accurate