I went to the library and borrowed _____reference books they have on the subject.A.that B.which C.what D.where答案：ＣＷＨＹ？
热心网友
主语从句用what引导。
热心网友
I went to the library and borrowed _____reference books they have on the subject.A.that B.which C.what D.where whatthey have 做定语修饰reference books, 选择a和b是错误的因为主语从句一般不用that 和which引导 borrow 后面的部分全部做宾语。
热心网友
what they have 他们所有的