你什么时候回巴黎？

When are you ___going ___back to Paris?

开始下雨了，所以我回去拿我的钥匙。

It had started to rain so I ___went ___back for my keys.

所以我回到教室，拿起我的包回家了。

So I ___went ___back to the classroom, picked up my bag and went home.