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
A.needn't do
B.needn't have done
C.musn't do
D.musn't have done
问题解答：
我来补答展开全文阅读