as it turn out to be a small house party,we__so formally求大神帮助as it turn out to be a small house party,we__so formally a need not have dressed up b must not have dress up c did not need to dress up d must not dress up 为什么答案选a不选c 两者区别
问题描述：
as it turn out to be a small house party,we__so formally求大神帮助
as it turn out to be a small house party,we__so formally a need not have dressed up b must not have dress up c did not need to dress up d must not dress up 为什么答案选a不选c 两者区别
答
need not have dressed up 本不必打扮得那么正式,（但是实际上已经打扮得很正式了）C没这个意思