今天在网上搜索一道逻辑题时读到一段话，觉得非常受用，主要是针对一些evaluate arguement的题目，放上来和大家分享：
Quote from "ManhattanGMAT forum":
Evaluating the argument means that you actually have information to know more about
whether the argument is valid. If the argument is more valid, then you're strengthening the argument; if the argument is less valid, then you're weakening the argument.
If we were actually to do the research to gain the information represented in the correct answer, then we would be able to determine whether the argument is more or less valid.
Note that, of course, they don't actually tell us which way it goes - each choice just says "
whether blah blah blah" meaning the actual information could go either way if the research were done. But if that research were done, and we had the results, then the effect would be to either strengthen or weaken (we don't know which!) the argument!
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Unquote
结合自己做题时的一些问题，有时答案里出现和原文很相似的一段话，因为觉得相关，立即就会将此作为选项, but actually it is wrong, because that answer choice doesn't help, as it addresses the one possibility that has already been considered by the passage.
放道题目给大家感受一下，这也是上面那段话出处的原题：
Most of the world's supply of uranium currently comes from the mines. It is possible to extract uranium from seawater, but the cost of doing so is greater than the price that Uranium fetches on the world market. Therefore, until the cost of extracting uranium from seawater can somehow be reduced, this method of obtaining uranium is unlikely to be commercially viable.
Which of the following would it be most useful to determine in evaluating the argument?
a. Whether the uranium in deposits on land is rapidly being depleted
b. Whether most uranium is used near where it is mined
c. Whether there are any technological advances that show promise of reducing the costs of extracting uranium from seawater d. Whether the total amount of Uranium in seawater is significantly greater than the total amount of uranium on land
e. Whether uranium can be extracted from freshwater at a cost similar to the cost of extracting it from seawater.
-- by 会员 danielleydd (2012/3/3 16:56:39)