答案应该是C。 应为这里的 是系动词,后接 (to be) + n/ adj.意为“证明是”。
eg. He proves (to be) innocent.
My advice proved (to be) wrong.我的意见证实是错的。
该词也有实义动词的用法, 为及物动词, “证明”。
eg. He has proved his courage in battle.他已在战斗中证明了自己的勇气。
he proved that Tom did not break into resident’s house
It proves that he is innocent.
D What he had said 作为主语,此句为被动语态,因为事情已发生,所以用过去式。译为:他在会上所说的话被证实是真的