问题补充：
— Li Lin hasn’t turned up yet, but he promised to come to the party.
— He home. He is a man of keeping his word.
A. can’t leave
B. won’t be leaving
C. could have left
D. must have left
答案：
A. can’t leave
B. won’t be leaving
C. could have left
(答案→)D. must have left
解析：句意：——李林还没来，但他答应过要来参加聚会的。——他肯定已经从家里出来了。他可是个信守诺言的人。从He is a man of keeping his word中可以看出，李林肯定已经出发来参加我们的晚会，这是对已发生的事肯定的推测，故用情态动词完成式。注意must用作推测意义时，不能用于否定式和疑问句。can’t leave肯定没有离开；won’t be leaving将不愿意离开；could have left本来可以离开的。
