He failed his exam,_ proves that he wasn't working hard ebough.
问题描述：
He failed his exam,_ proves that he wasn't working hard ebough.
A.what B.of which C.which D.this
想问问C不可以选么?
答
答案应该选C ,
两个句子直接必须有and ,如果有and ,D 才可以正确,因为,这个句子本身语态不对,应该是 proved.
如果非要选个答案,那就是C ,用which 一点问题也没有.