As it turned out to be a small party,we____so formally答案是选“need't_英语解答

As it turned out to be a small party,we____so formally
答案是选“need't have dressed up'
为什么不选 did not need dress up ,如果在need后加上to可以选吗?

人气：213 ℃　时间：2020-04-05 22:47:25

解答

这里表示的是本不需要
而且这里的need是情态动词
作实义动词是加to do