——I have seen the film Titanic already.——When __——I have seen the film Titanic already.——When ___you ___it?为什么填did see,不填have seen?

问题描述:

——I have seen the film Titanic already.——When __
——I have seen the film Titanic already.
——When ___you ___it?
为什么填did see,不填have seen?