作者：英吉
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
题目分析：这几个选项最大的不一样就是时态不同，根据语意确定句子应该表达的是一个客观事实，五个选项中应该是一般现在时表达的是一个客观事实，选B
