? ?不定式完成式在句中可作主语、宾语、定语、状语、宾语补足语、主语补足语和复合谓语。? ? 动词不定式完成式作主语时，主要用于 It 作形式主语的句型。如：? ? It would have been amusing to have gone to the exhibition. 当时要是去看展览会那一定是很有趣的。（实际上没有去）? ? It was very good of you to have listened to me. 你听了我的话，这很好。? ? Oh, what a mistake it is to have come ! 啊，到这里来真是一个天大的错误！? ??动词不定式完成式作宾语时，有两种句型：? ? subj.+vt.+inf.phr.? ??subj.+vt.+it+宾语补足语+inf.phr.（真正宾语）? ? I regret to have been the cause of all this trouble. 很抱歉这一切麻烦都是由于我的原因而引起。? ? They thought it a pity not to have invited her. 他们认为没有邀请她真是很遗憾。? ? She felt it an honour to have taken part in the work. 她感到参加这一工作是一种荣幸。? ?（待续）