a  What did you do after school?放学后你干什么了？

 I saw a movie after school.放学后我看电影了。

b  What did you do after school? 你放学后干什么了？

I went to the museum after school.放学后我去博物馆了。

c  What did you do before dinner?晚饭前你干什么了？

 I did my homework before dinner.晚饭前我做作业了。

d  What did you do after dinner?晚饭后你干什么了？

 I brushed my teeth after dinner.晚饭后我刷牙了。