菜鸟兼新人问一个简单的问题

jzjxbd

OG11第7题

7.     Carnivorous mammals can endure what would otherwise be lethal levels of body heat because they have a heat-exchange network which kept the brain from getting too hot.

(A) which kept

(B) that keeps

(C) which has kept

(D) that has been keeping

(E) having kept

Idiom + Verb form

The two underlined words contain two separate errors. The pronoun which introduces nonrestrictive clauses, which include information relevant but not critical to an understanding of the sentence. The pronoun that introduces a restrictive clause, which is critical to understanding the sentence because the clause defines its antecedent. Here, the clause following which defines heat-exchange network, so that must be used in place of which. The use of the past tense (kept) is incorrect because a current situation is discussed; the present tense (keeps) is consistent with the other verbs in the sentence.

为什么说这个which 引导非限制性定语从句呢，它前面又没有“，”不是which也可以引导限制性的定语从句的吗，引导非限制性的定语从句不是前面要有逗号，为什么一定要改成THAT呢？

请前辈高人们帮帮忙解释一下，谢谢！

[此贴子已经被作者于2008-6-14 9:21:25编辑过]

AlienX

GMAT中的non-restrictive clause都是有comma...(as far as I know)
"which"在GMAT中只用在non-restrictive clause; 在一般英語中, which的用法可以自由很多...;-)

jzjxbd

谢谢