gmatprep里得一道逻辑,完全看不懂

Matrixrl

以下是引用mbz在2006-11-9 4:45:00的发言：

I would like to ask Matrixrl:

In choice D, is it previously "unknown" crystalline structure or "known" in the original question?

If it is previously unknown, it doesn't make sense, since previously unknown means it is now known.

On the other hand, if it is previously known, then it can weaken the arguement by saying that there is no need to do any test any more b/c the structure has already been known.

这题目就这么表达的,我没动过,我到现在还没怎么理解

uibewsj

俺是这样想的，不知道对不对：

前提1：在实验室里能合成F，并且只能在一定温度压力等条件下才能合成。
前提2：新发现了天然的金属里也有F.
结论：可以推测F形成时期地壳的温度压力等条件。
削弱：两种F的结构根本不一样，这在做推测的时候并不知道。（实验室里的是spherical molecules made entirely of carbon，天然的是crystalline structure.）

boochxu

ding

ptr07

in this question, we need to break the bridge. We can say nobody know the condition in which the fissue formed.
D correctly list one that can not be explained by the current scientific experiments, hence it is the Correct answer

huashengke

是的，b里面错在了some上面。

flywhere812

up