LSAT16-3-18-->bigmouse转移

sammen

18. In experiments in which certain kinds of bacteria were placed in a generous supply of nutrients, the populations of bacteria grew rapidly, and genetic mutations occurred at random in the populations. These experiments show that all genetic mutation is random.
Which one of the following, if true, enables the conclusion to be properly drawn?
(A) Either all genetic mutations are random or none are random.
(B) The bacteria tested in the experiments were of extremely common forms.
(C) If all genetic mutations in bacteria are random, then all genetic mutations in every other life form arc random also.
(D) The kind of environment in which genetic mutation takes place has no effect on the way genetic mutation occurs.
(E) The nutrients used were the same as those that nourish the bacteria in nature.
这道题目看了NN们的解释，还有一点不太明白。D我认为也是可以做assumption的啊。D选项本身是排除了一个他因的可能，加强了；取非，那么指出试验的结果有其他的影响因素，weaken了。这不是很符合assumption题的结果吗？请NN指教，我是不是走火入魔啦?

likui

是不是选C呀？“由特殊（bacteria）到一般（every other life form ）”

这样就到了文中的conclusion：These experiments show that all genetic mutation is random.