题目内容：

What are you looking for?I’m looking for the CD about EXO ___ I bought yesterday.
为什么只能用that不能用which

优质解答

都可以用,原因一是 这里that/which做从句的宾语,也就是i　bought　the　CD．that／　which这就就是代指the　CD的.且可以省略.原因二是先行词 the　CD　前面没有任何修饰词,当然that和which　都可以了.