非限和限 定语

abc791201064

是不是题目中重要的名词（或者出考题地方的名词）  都要有限定性名词呢？  假如题目中只有一个非限  必须改成限定性的？

另外一个是  除了 which  that外，  后置定语、放在N前面的单个adj算非限还是限？
求大牛



比如下面这个例子

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

答案是B