题目内容：

This is the only book ________I bought last year. A.which B.that C.what D.Both A and B
the key is B
who can tell me why?

优质解答

额.好简单的.
book在后面的分句中作宾语,后面的句子缺宾语,所以用which或that.
在看前面的句子,先行词被the only修饰,只能用that .
像这样的还有all,every ,some,much,just.等,被这些词修饰了,都只能用that .
就是这样的了,