----You didn’t wait for Mr. Smith last night, did you?
-----Yes, but we . He didn’t return home at all.
A. don’t have to
B. didn’t need to
C. needn’t have
D. should have
网友回答
A. don’t have to
B. didn’t need to
(答案→)C. needn’t have
D. should have
解析：考查情态动词用法。句意:昨天晚上你没有等Mr Smith，是吗？—不，我等他了。可数我们本不需要这样做。他昨天晚上根本没有回来。Needn’t have done本不需要做某事，实际上却做了；should have done本应该做某事，实际上却没有做；本题Mr Smith没有回来，我们本不必等他的。故C正确。