I sent an MP4 to Alice by mail just now.You___so.She is coming tomorrow
问题描述:
I sent an MP4 to Alice by mail just now.You___so.She is coming tomorrow
A.needn't do
B.needn't have done
C.musn't do
D.musn't have done
答
B
needn't have done sth 表示过去没必要做什么,而事实上已经做了