一.情态动词的现在完成式的用法
情态动词现在完成式主要有两个功能:表示已经发生的情况和表示虚拟语气。在这两个方面must/mustn\'t,; can/cann\'t; need/needn\'t; may/mayn\'t; might/mightn\'t; should/shouldn\'t; ought等情态动词+完成式表示的意思是有一定区别的
1.表示已经发生的情况。
1) must have+过去分词,表示对已发生情况的肯定推测,译为“(昨天)一定……”。如:
My pain apparent the moment I walked into the room, for the first man I met asked sympathetically:” Are you feeling all right?”
A. must be B. had been C. must have been D. had to be
(答案为C.