我有问题想问你，you can not imagine how much we respect Professor Johnson now,__we used to laugh at so much A.who B.which C.where D.when答案是C我想问一下who为什么不能选，语法上who和whom都可以做宾语代指人为什么答案不能选A
还有一个问题，Samuel survived when the car __he was a passenger in turned off the road and hit a tree A.where B.that C.as D.why答案选择B B和C都可以代指物是不是as一般都是用在非限制性定语从句
