一道困惑的逻辑支持归纳题

寂寞的自由 · 发表于 2003-12-31 07:45:00

4. Most geologists believe oil results from chemical transformations of hydrocarbons derived from organisms buried under ancient seas. Suppose, instead, that oil actually results from bacterial action on other complex hydrocarbons that are trapped within the Earth. As is well known, the volume of these hydrocarbons exceeds that of buried organ-isms. Therefore, our oil reserves would be greater than most geologists believe.Which of the following, if true, gives the strongest support to the argument above about our oil reserves? A-àE
(A) Most geologists think optimistically about the Earth's reserves of oil.
(B) Most geologists have performed accurate chemical analyses on previously discovered oil reserves.
(C) Ancient seas are buried within the Earth at many places where fossils are abundant.
(D) The only bacteria yet found in oil reserves could have leaked down drill holes from surface contaminants.
(E) Chemical transformations reduce the volume of buried hydrocarbons derived from organisms by roughly the same proportion as bacterial action reduces the volume of other complex hydrocarbons.

答案是E，可是我觉得A对哦！而且E中的黑体字部分同原文中的比较句内容矛盾啊，谢谢大家

mindfree · 发表于 2004-1-1 10:00:00

E is right. You might have misunderstood the question. The argument is as follows:

the volume of these hydrocarbons exceeds that of buried organisms ==> if oil was from the other hydrocarbon, instead of the buries organisms, there would be more oil (because the "raw material" was in larger volume)

E is right because it the process reduced the "raw material" by the same percentage, say, both process reduced 100 tons of both hydrocarbons to 1 gallon of oil, more "other hydrocarbon" will produce more oil, supporting the argument.

If, say the hypothesized process reduced the hydrocarbon by a greater percentage, say 100 tons would be reduced to 0.5 gallon of oil, while the other process at 100 tons to 1 gallon, then even when the "other hydrocarbons" were in larger volume, it would not necessariy produce more oil.

Hope that I explained it.

crusaders · 发表于 2004-1-5 02:50:00

看了MindfreeGG的解答
换个角度说一下 :]
R(转化率)
R(og)--->C1--->O1 C1xR(og)---->O1(用方法1得出的oil储存量)
R(ba)--->C2--->O2 C2xR(ba)---->O2(用方法2得出的oil储存量)
FACT: C1Conclusion: O2>O1
答案E: R(og) 大约= R(ba)
如果比率不一样的化,所给的事实和结论就不能有效的结合到一起.
Fact+support--->Conclusion
既C2xR(ba)>C1xR(og)
请大家指正..

nomoreets · 发表于 2004-1-8 20:06:00

大侠说的已经很好了,我来说点大白话:
E指出了重要的一点,即: 如果A和B都能转化为C,且B储量大于A,若要说B更牛,必要条件是B转化为C的时候不会损失的比A转化为C的时候多!
其实就是这么简单.

A是无关选项.

一道困惑的逻辑支持归纳题

一道困惑的逻辑支持归纳题

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