不定式啊!be surppose to我不懂什么语境下用to have doneto have done 应用在主动和已经完成的情况下那么you are supposed to take part in the party in time 与原先句子 有什么区别？be suppose to do应该某事 相当于should第一个相当于should have done 本应该做某事没做哦，谢谢