问题
选择题
— 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。
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”。