这个书包是有人下课后落下的。

This bag was left behind after the class.

《牛津词典》

所以我经常在课后做数学测试。

So I often do math tests after class.

youdao

我经常在课后打乒乓球。

I often play table tennis after class.

youdao

Obviously, it's not going to be a question identical to something you've done, but it's going to cover that subject matter.

当然不会是你做过的,课后作业的题目，但是会涉及到相关内容。

麻省理工公开课 - 固态化学导论课程节选

Okay, if anybody has questions about this one in particular you can ask Christina after class or at a different time.

如果大家有问题想单独问她,可以在下课后或其他时间问她

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

But I am telling you this after you already signed up for the class so it is too late to leave.

我在你们选了这门课后才挑明,想退课也晚了。

哈佛公开课 - 幸福课课程节选