离开前请确保关闭你的电脑。

Make sure you ___shut ___down your computer before you leave.

机组人员关闭了飞机四个引擎中的一个。

The crew ___shut ___down one of the four engines on the plane.

我关闭了电脑，然后打电话给我妈妈。

I ___shut ___down the computer and called my mom.