对于07PREP的一道逻辑题的解法，和前人的理解不是很一样，求斑竹指点！！！！

DUKB24

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 Uraniumfetches 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.

以下是高智威老师的解释：
思考：1. 文中告诉我们，是否“this method is unlikely to be commercially viable”，主要是比较uranium from seawater 和 uranium on the world market (uranium from mines),谁的成本比较高（也就是原因）。换句话说，from seawater的成本高，那就commercially viable, 否则不是；2. 所以，正确答案一定与原因相关，并且不能有无关名词。


以下是我的看法：对于高智威老师的说法很是不解，虽然我不否认他的做题技术真的很强
我个人的分析：Premise:the cost of extracting uranium from seawater can(cannot) be reduced
            Conclusion:this method of obtaining uranium is likely(unlikely) to be commercially viable.
这里A选项的出现，就根据我个人的想法，是起到一个充分条件不发生，必要条件也能发生的情况么？
就是说资源在陆地的有限，如果被消耗了，cost 不用降下来，海水提取也一定是commercially viable的？？？
对于C选项，很多人都说technology这里无关名词，如果改一下，改成there are some ways that can reduce the cost of extracting uranium from seawater.这样是不是也不选？因为这样的话也只是原文假设的重现，对于conclusion没有一点作用.


个人对我的分析思路不是很确定，支持的话帮顶一下，真心跪求大N或斑斑帮忙解答..最近都在专攻逻辑呢，搜了好久帖子都没怎么见分析这题的

DUKB24

真心求指点

DUKB24

DUKB24

UPUPUP

sdcar2010

To put this problem in another way of saying, the conclusion is:
If the cost of extracting U from seawater does not drop, this seawater-based method is not likely to be used commercially.

A) simply tells you whether there is another factor affecting the assumption of the above statement: the land-based U is always available.

shirryzhan

Premise: Extracting uranium from seawater is much more expensive than that sold on the market.

Conclusion: The method of extracting uranum from the seawater is viable only if the its cost declines.

What contributes most to evaluate the argument?

Lets consider C.

Tech makes the method of extracting uranium from seawater cheaper. Absolutely, the new method will be commercially viable. And Choice C does no harm to the argument, maybe slightly support it. (BUT actually, it doesn't make big contribution to the argument, because the speaker has already considered the possibility that the sea-uranium method would be cheaper)

Then A.

Uranium got from land is being depleted. Then, it is very likely that even though the sea-uranium method would not become cheap, there would be good incentive to exploit sea-uranium from now. Thus, A definitely counterargues the conclusion.



On the other hand, even though new method is getting cheap, how much possibility that the merchants now will use it? Who knows?!

pinkking

这种题目的Trick就在于，会出现一个很有误导的选项，如果不注意到问题问的点的话，就很容易选到那个选项。

楼主你看看题目的结论是啥先啊，题目说的是“除非海水提取那啥物质的成本能够降下来，否则这种技术就不可能大规模推广”，那么这个点是在于，这个技术能不能推广跟成本有直接关系，成本太贵，那么就不可能推广。

现在题目要你选一个undermine的选项，那么你要攻击的点就是，就算成本降不下来，那么这个技术也是能推广滴。为啥呢？就因为陆地上的都消耗完了，大家别无选择，只能提取海水里面的了。就算成本很贵，那也是毛办法呀……

你再看看C选项的，完全就无关啊。技术能不能把价格降下来又如何呢，降不下来，也不能说明这个技术一定会推广啊。人家还是能从陆地上面提取嘛……

macrostrong

我觉得楼上关于正确选项的分析是对的，但是关于为什么不选C，我说说自己的看法。

题目中：Therefore, until the cost of extracting uranium from seawater can somehow be reduced, this method of obtaining uranium is unlikely to be commercially viable.
有一个Until，意思是在从海水中提取uranium的成本降下来之前，从海水中提取uranium是否有可行的商业价值。这里的point就是，在成本降下来这件事发生之前，这个argument是否成立。

而C选项说的是可能存在这样一种技术能够降低成本，说的是成本降下来之后的事情。 成本降下来以后，自然就可能具有商业价值了。 这个argument中，如果把 until the cost of extracting uranium from seawater can somehow be reduced这个删掉，那么A,C就是正确的；否则就是A正确。

Feelalive

sdcar2010 发表于 2012-5-6 04:32
To put this problem in another way of saying, the conclusion is:If the cost of extracting U from sea ...

sdcar大大，膜拜之
嘟嘟锅，其实我也觉得C挺好，但是technology应该是irrelevent