超市刷卡机多少钱一台:must have done 和 must do 有什么区别！哪一个是表示对过去的猜测呢？

must＋have done 句型 must have done 和 must do 有什么区别！哪一个是表示对过去的猜测呢？ must have done 和 must do 有什么区别！哪一个是表示对过去的猜测呢？ must have done 和 must do 有什么区别！哪一个是表示对过去的猜测呢？ have been doing和have done have sth. done 和 have sb. do 有什么不同？ He must have done it last night,____he ? 这个反意疑问句怎么做啊 have sth to be done和have sth done的区别是什么？ shall have done和would have done在虚拟语气句中是什么意思？ 请问shouldn't have done和might not have done 在此题中的区别？