问题补充:
— 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:
(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”。