as it turned out to be a small house party,we ______ so formally.

问题描述:

as it turned out to be a small house party,we ______ so formally.
A.needn't dress up
B.shouldn't dress up
C.were not necessary to dress up
D.needn't have dressed up 为什么不选c

it is / was (not) necessary FOR us to dress up不能用在虚拟语气.所以答案是D谢谢,那为什么a不行呢Aneedn't dress up------指的是“将来”的动作。turnED----指的是“过去”的动作,所以A是错的 D. needn't have dressed up------指的是,过去没有必要做,但的确做了。