GMAT语法小课堂：到底可以多模糊？.

　　Some Ambiguity Is Acceptable有些特定的模糊是可以接受的，首先，在规范的英语写作中，一个句子中的每个代词应该只有一个先行词。也就是说，假如句子中有两个it，其中一个代表A，另外一个代表B，这种用法是错误。

　　其次，GMAT语法倾向于用same class的代词代表同一个名词。It与its是同一class，they，them和their是同一class。但是，这只是优先考虑的答案，并不是排除答案的规律。GMAT中有一些句子，用同一class里的代词指代不同的名词。

　　例如：

　　Researchers claim to havedeveloped new “nano-papers” incorporating tiny cellulose fibers, which THEY allege give THEM the strength of cast iron.

　　They，是谁声称?当然是研究者，所以they指代researchers;而them是指研究者吗?让谁更强韧呢?当然是纳米纸了，所以them指代nano-papers。

　　这在GMAT考试中是可以接受的，如果选项中没有更加清晰且语法正确的句子，那么上面的句子就是最优选项。

　　为减少模糊，可以改成下面的写法

　　Right: Researchers claim tohave developed new “nano-papers” incorporating tiny cellulose fibers, whichgive THESE MATERIALS the strength of cast iron, according to the researchers.

　　再次，If you spot a split between a pronoun and a regular noun, chancesare good that the correct answer will use the regular noun, since that usagewill prevent any possible misreading of a pronoun.就像上面的例子，名词nano-paper与代词them不相邻，这样容易造成模糊，所以用regular noun “thesematerials”而不是代词。

　　最后，选项中只含一个代词，却有很多可能的先行词，怎么判断?

　　problem set in chapter 7

　　Bold all the pronouns in the followingsentences. Underline the antecedent, if there is one, of each pronoun.If you notice any pronoun errors in a sentence, correct the sentence byaltering the pronoun(s). Explain what rules are violated by the incorrectsentences. If a sentence is correct, mark it with the word CORRECT.

　　1. When the guestsfinished their soup, they were brought plates of salad.

　　CORRECT. 句中guests是代词their和they的先行词。

　　有没有人像楼主一样疑惑为什么they were brought要用被动语态，然后想应该是东西被拿上来。但是客人是被服务的，所以这里应该用被动，也没有代词上的歧义。

　　2. All students need his or her own copy of the textbook in order to take the class.

　　All students是his or her的先行词。然而all students是复数，所以代词也应该用复数形式的their

　　改为：All students need their own copy of the textbook in order to take the class.

　　3. When tetrapodsdeveloped lungs, theybecame the first amphibians capable of surviving onland.

　　Tetrapods四足动物，amphibian两栖动物

　　CORRECT. Tetrapods是they的先行词。有些同学也许会疑惑，they前面有两个名词复数tetrapods和lungs，这难道不会造成模糊吗?GMAT允许这样的模糊，因为从逻辑上讲lungs不可以是they的先行词。