1. 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.
2. The interstitial nucleus, a subregion of the brain’s hypothalamus, is typically smaller for male cats than for female cats. A neurobiologist performed autopsies on male cats who died from disease X, a disease affecting no more than .05 percent of male cats, and found that these male cats had interstitial nuclei that were as large as those generally found in female cats. Thus, the size of the interstitial nucleus determines whether or not male cats can contract disease X.
Which one of the following statements, if true, most seriously weakens the argument?
(A) No female cats have been known to contract disease X, which is a subtype of disease Y.
(B) Many male cats who contract disease X also contract disease Z, the cause of which is unknown.
(C) the interstitial nuclei of female cats who contact disease X are larger than those of female cats who do not contract disease X.
(D) Of 1,000 autopsies on male cats who did not contract disease X, 5 revealed interstitial nuclei larger than those of the average male cat.
(E) The hypothalamus is known not to be causally linked to disease Y, and disease X is a subtype of disease Y.
18. Modern navigation systems, which are found in most of today’s commercial aircraft, are made with low-power circuitry, which is more susceptible to interference than the vacuum-tube circuitry found in older planes. During landing, navigation systems receive radio signals from the airport to guide the plane to the runway. Recently, one plane with low-power circuitry veered off course during landing, its dials dimming, when a passenger turned on a laptop computer. Clearly, modern aircraft navigation systems are being put at risk by the electronic devices that passengers carry on board, such as cassette players and laptop computers.
Which one of the following, if true, LEAST strengthens the argument above?
(A) After the laptop computer was turned off, the plane regained course and its navigation instruments and dials returned to normal.
(B) When in use all electronic devices emit electromagnetic radiation, which is known to interfere with circuitry.
(C) No problems with navigational equipment or instrument dials have been reported on flights with no passenger-owned electronic devices on board.
(D) Significant electromagnetic radiation from portable electronic devices can travel up to eight meters, and some passenger seats on modern aircraft are located within four meters of the navigation systems.
(E) Planes were first equipped with low-power circuitry at about the same time portable electronic devices became popular.作者: cook 时间: 2002-10-24 09:13
1. Conclusion: if researchers find a trace of mercury in his hair, we can conclude that this hypothesis is correct.The hypothesis is that venereal disease caused his deafness.
Premise: 1) traces of mercury were found in his hair ; 2)Since mercury was commonly ingested in Beethoven’s time to treat venereal disease
Asking Assumption:
A. mercury can be eliminated ---> Unrelated!
C.an effective treatment ---> Unrelated!
Epsychological problems )of the same (severity) as Newton’s ---> Unrelated
Let See B and D:
D:Mercury poisoning can cause deafness in people with venereal disease. That is, Mercury + Venereal disease can cause deafness. The information can not lead us to that conclusion "venereal disease caused his deafness". --- Maybe we can wait to see B.
(B) Some people in Beethoven’s time did not ingest mercury. Whether it belongs to " NOT +Weakness" type assumption. You can try.
Yes, it is the right answer: if Some people in Beethoven’s time ingest mercury , then You can not deduce that the patient found mercury with his hair is effected Venereal disease, eventually, weaken the conclusion that if you find mercury in some's hair, then venereal disease caused his deafness.
Choose B. Not easy! but done! Hi, only wish I could be so cool during my test!!作者: jjjjjj 时间: 2002-10-24 11:40
你的答案是正确的，可我还是不明白。
我觉得原题中，历史学家的推理是：VENEREAL导致DEAF，而MERCURY 在那时是用来治VENEREAL的。因此如果在头发中检测到MERCURY，就可推出BEETHOUEN有VENEREAL， 进而论证VENEREAL导致DEAF。我的理解对不对啊？
如果是这样，那A为什么不对啊？ STILL DONT UNDERSTAND。。。作者: tongxun 时间: 2002-10-24 11:58
psychological problems )of the same (severity) as Newton’s ---> Unrelated