Frobisher, a sixteenth-century English explorer, had soil samples from Canada's Kodlunarn Island examined for gold content. Because high gold content was reported, Elizabeth I founded two mining expeditions. Neither expedition found any gold there. Modern analysis of the island's soil indicates a very low gold content. Thus the methods used to determine the gold content of Frobisher's samples must have been inaccurate. Which of the following is an assumption on which the argument depends? A. The gold content of the soil on Kodlunarn Island is much lower today than it was in the sixteenth century. B. The two mining expeditions funded by Elizabeth I did not mine the same part of Kodlunarn Island. C. The methods used to assess gold content of the soil samples provided by Frobisher were different from those generally used in the sixteenth century. D. Frobisher did not have soil samples from any other Canadian island examined for gold content. E. Gold was not added to the soil samples collected by Frobisher before the samples were examined. 我不明白为什么会选E. 我的思路是这样的:我对E取非,但并不使原结论不成立,故我认为不对。 若把not盖住,即:在Samples被测前,gold是被加到sample里去的,而不是sample里本身就含的,故,当年Frobisher检测到sample里金的含量高是假象,是错误的。这与结论:当年Frobisher的检测方法是错误的,是不谋而合,故对E取非后并未使原结论不成立,则E不应该是答案啊。 另外,本文提到了2个检测方法,一个是当年Frobisher用的检测方法,另一个是modern analysis采用的检测方法,不知道最后一句提到了the methods used to...是指哪一个方法呢? 请牛人不吝指点迷津,叩谢!
[此贴子已经被作者于2009-1-6 14:45:24编辑过] |