—Mary’s got crazy and has been sent to the mental hospital. Did you tell her boss about that?
—Yes, but I her husband first.
A. can have told
B. should have told
C. need have told
D. must have told
网友回答
A. can have told
(答案→)B. should have told
C. need have told
D. must have told
解析：考查情态动词用法。Can have done可能做了某事；Should have done本应该做某事，实际上却未做；need have done本需要做某事，实际上却未做；must have done一定做了某事；句意：—Mary疯掉了，已经被送到了精神病医院。你把这件事情告诉她的老板了吗?—是的。但是我本应该先告诉他丈夫的。BC两项是虚拟语气，表示对过去的虚拟。AD两项表示对过去情况的推测。