题目

— I sent him the dictionary by mail this morning . —You ____ that; he''s coming tomorrow afternoon . A . needn''t have done B . didn''t have to C . needn''t do D . mustn''t do 答案：A。 解析: 表示“不必做某事但事实上已做了，”应用“needn''t +不定式的完成式”。

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