— I sent him the dictionary by mail this morning .
—You that; he''s ing tomorrow afternoon .
A. needn''t have done
B. didn''t have to
C. needn''t do
D. mustn''t do
网友回答
(答案→)A. needn''t have done
B. didn''t have to
C. needn''t do
D. mustn''t do
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”。