LSAT-16－2－12 以前讨论过，但还有问题问

12. Individual pyrrole molecules readily join together into larger molecules called polypyrroles. If polypyrroles form from pyrrole in the presence of zeolites, they do so by attaching to the zeolite either in lumps on the outer surface of the zeolite or in delicate chains within the zeolite抯 inner channels. When zeolite changes color from yellow to black, it means that on or in that zeolite polypyrroles have formed from pyrrole. 【Yellow zeolite free of any pyrrole was submerged in dissolved pyrrole. The zeolite, turned black even though no polypyrroles formed on its outer surface. 】
If the statements above are true, which one of the following must on the basis of them be true?
(A) Polypyrroles had already formed on or in the zeolite before it was submerged.
(B) Lumps of polypyrrole attached to the zeolite were responsible for its color change.
(C) At least some of the pyrrole in which the zeolite was submerged formed polypyrrole chains.
(D) None of the pyrrole in which the zeolite was submerged attached itself to the zeolite.
(E) Little, if any, of the pyrrole in which the zeolite was submerged reached the zeolite's inner channels.

我想问一下这最后两句到底什么意思。是倒数第二句省略了when，和最后一句组成一句话吗？如果是单独的两句话，其间的关系又怎么解释呢？突然蹦出来这两句搞得我晕头转向。

怎么前面说when zeolite changes color to black,it means....，这里最后一句又说zeolite turned black even though no poly- formed on  its outer surface.呢？

从WHEN以后共三句话。

1。当Z从黄色变成黑色，意味着在Z的表面或里面已形成多P（polypyrroles）

2。没有任何P的黄色Z浸在溶解P中

3。Z变黑，尽管在Z表面没有多P形成。

第2句和第3句实际为 if 关系。这是选言判断。否定一选言支，必肯定另一选言支。即里面必形成多P，它为链状。故选C

什么是选言判断呀？

哦～懂了，2，3句其实是描述现在给我们的情况，让我们判断发生这种情况的原因是inner形成poly。

thax a bunch!