以下是引用cloud0819在2004-9-4 15:35:00的发言:Q9: Although exposure to asbestos is the primary cause of mesothelioma, a slow-developing cancer, researchers believe that infection by the SV40 virus is a contributing cause, since in the United States 60 percent of tissue samples from mesotheliomas, but none from healthy tissue, contain SV40. SV40 is a monkey virus; however, in 1960 some polio vaccine was contaminated with the virus. Researchers hypothesize that this vaccine was the source of the virus found in mesotheliomas decades later. Which of the following, if true, most strongly supports the researchers’ hypothesis? A. SV40 is widely used as a research tool in cancer laboratories. B. Changes in the technique of manufacturing the vaccine now prevent contamination with SV40. C. Recently discovered samples of the vaccine dating from 1960 still show traces of the virus. D. In a small percentage of cases of mesothelioma, there is no history of exposure to asbestos. E. In Finland, where the polio vaccine was never contaminated, samples from mesotheliomas do not contain SV40. 我觉得C。E都是加强,如何区分?
题目是说
原因:1960年的疫苗感染了这个病毒。
科学家的假设是:1960年的那个疫苗是现在出现这个病毒的原因。
E的意思是:有可能,如果polo疫苗没有感染这个病毒,那么这个病症就不含这个病毒。
E的意思首先很含混,它并没有指出疫苗和这个病毒的任何因果关系,原因和结果之间有太大的鸿沟需要弥补。实际上这更像是个逻辑上有问题故意设置的干扰选项,根本无法从已知条件中推出疫苗和病毒的关系。
其次,假设这句话逻辑正确,那么它只是反对了“这个病和sv病毒有关”的事实,因为这是从这句话中唯一能够得到的推论。而文中假设的前提显然是这个病和sv有关。 E显然错误,答案是C
[此贴子已经被作者于2005-9-6 17:18:31编辑过] |