20. A rise in the percentage of all 18-year-olds who were recruited by the armed services of a small republic between 1980 and 1986 correlates with a rise in the percentage of young people who dropped out of high school in that republic. Since 18-year-olds in the republic are generally either high school graduates or high school dropouts, the correlation leads to the conclusion that the republic’s recruitment rates for 18-year-olds depend substantially on recruitment rates for high school dropouts.
Which one of the following statements, if true, most weakens the argument?
(A) A large number of 18-year-old high school graduates were recruited for the republic’s armed services in 1986 than in 1980.
(B) Many of the high-technology systems used by the republic’s armed services can be operated only by individuals who have completed a high school education.
(C) Between 1980 and 1986 the percentage of high school graduates among 18-year-olds recruited in the republic rose sharply.
(D) Personnel of the republic’s armed services are strongly encouraged to finish their high school education.
(E) The proportion of recruits who had completed at least two years of college education was greater in 1986 than in 1980.
请问各位牛牛,这道题答案是选C,我选的B,到底怎么回事呢?C怎么看也不象是weaken啊
21. Historian: We can learn about the medical history of individuals through chemical analysis of their hair. It is likely, for example, that Isaac Newton’s psychological problems were due to mercury poisoning; traces of mercury were found in his hair. Analysis is now being done on a lock of Beethoven’s hair. Although no convincing argument has shown that Beethoven ever had a venereal disease, some people hypothesize that venereal disease caused his deafness. Since mercury was commonly ingested in Beethoven’s time to treat venereal disease, if researchers find a trace of mercury in his hair, we can conclude that this hypothesis is correct.
Which one of the following is an assumption on which the historian’s argument depends?
(A) None of the mercury introduced into the body can be eliminated.
(B) Some people in Beethoven’s time did not ingest mercury.
(C) Mercury is an effective treatment for venereal disease.
(D) Mercury poisoning can cause deafness in people with venereal disease.
(E) Beethoven suffered from psychological problems of the same severity as Newton’s.
答案是B.我同意,但是我选的A.我觉得A也可以.因为如果mercury可以被eliminated干净,那么就没办法知道原来贝多芬用过,也不能说他的VD被治过,也就无法得出他的耳聋是VD引起的.
请各位牛牛不吝赐教
[此贴子已经被作者于2003-10-27 19:02:43编辑过] | 
京公网安备11010202008513号 京ICP证101109号 京ICP备12012021号
发表于 2003-10-27 18:41:00
楼主