—Has Ham started out? He said he would join in the party.—He . He is a man who always keep

—Has Ham started out? He said he would join in the party.
—He . He is a man who always keeps his word.
A. must have left
B. need have left
C. should have left
D. could have left

(答案→)A. must have leftB. need have leftC. should have leftD. could have left解析：考查情态动词+have done，A是过去一定做了，B是过去本有必要做却没做，C是过去本应该做却没做，D是过去本可以做却没做，句意是：--Ham出发了吗？--他说他会参加聚会的。--他一定已经走了，因为他是守信的人。选A。

我明天再问问老师，叫他解释下这个问题