But the kind of exercise we did last time is a useful exercise for those of you who are Econ majors.

但是我们上节课做的练习,对经济学专业的同学是非常有用的

耶鲁公开课 - 博弈论课程节选

So you can scroll back through your history, which is also useful for time's sake.

所以我们可以滚回到我们的历史记录，这个可以节约我们的时间。

哈佛公开课 - 计算机科学课程节选

We'll talk a little bit about the principles of cellular physiology and then I'll move next time to talking about how you culture cells outside of the body and what that's useful for.

这节课我们讲一些,细胞生理学的一些原理,下节课具体讲,体外培养细胞的方法,及其用途

耶鲁公开课 - 生物医学工程探索课程节选