7.Carnivorous mammals can endure what would otherwise be lethal 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
og:which介紹一個非限定子句;that介紹一個限定子句
我的問題是:which前面沒有逗點,那應該是限定子句才對阿,為什麼og上說which子句是非限定子句?