________for Shanghai?Yes.And I'll come back in three months.

问题描述:

________for Shanghai?Yes.And I'll come back in three months.
可以用Did you leave

从回答看,“是的,而且我要三个月以后回来.”可以推理出,问话的意思是“你现在要去上海吗?”,所以,我认为这里不能用 Did you leave,而应当用进行时表示将来的用法,写成 Are you leaving .