They used light-sensitive molecules to turn on and off nerve cells in the deep brain structure of mice.

VOA: special.2009.04.07

We'll turn eventually to the question, how should we live in light of the fact that death is the end?

我们将最终将要探讨，在知道死亡就是终结的情况下我们该如何生存？

耶鲁公开课 - 死亡课程节选

We'll turn the light back on for a second here.

我们马上要开灯。

麻省理工公开课 - 化学原理课程节选

He could turn off a light and then jump into his bed before the room got dark.

VOA: special.2009.01.24

You don't need a light switch or a light bulb or an iPhone app to turn something on or off.

你不需要一个电灯开关,或者一个电管,或者打开关闭一个iPhone应用程序。

哈佛公开课 - 计算机科学课程节选