--I stayed at a hotel while in New York.-- Oh,did you?You ___ with Tom.a.could have stayed b.must have stayed为何选A,选B为何不可,表示你肯定跟TOM呆在一起

--I stayed at a hotel while in New York.-- Oh,did you?You ___ with Tom.a.could have stayed b.must have stayed为何选A,选B为何不可,表示你肯定跟TOM呆在一起
--I stayed at a hotel while in New York.
-- Oh,did you?You ___ with Tom.
a.could have stayed b.must have stayed
为何选A,选B为何不可,表示你肯定跟TOM呆在一起

--I stayed at a hotel while in New York.-- Oh,did you?You ___ with Tom.a.could have stayed b.must have stayed为何选A,选B为何不可,表示你肯定跟TOM呆在一起
表推测,语气更加委婉.这是外国人常表达的方法.

could have stayed 语气没有musthave 那么强烈，表示说话人委婉的语气用前者比较好