Turn off lights if it is unnecessary.

如果没有必要，请关灯。

youdao

Turn off lights, computers and air conditioners when you leave the office.

下班后关掉电灯、电脑和空调。

youdao

Encourage children to unplug toys and lights in their rooms and turn off lights throughout the house when not in use.

鼓励孩子在不需要的时候，拔下房间内玩具和灯的插头，并关掉屋子里的灯。

youdao

For the fourth year, people are being urged to turn off their lights for one hour to call attention to the issue of climate change.

VOA: special.2010.03.22

The first of these is rhythmic, so we're going to turn now -I guess we'll turn off the lights and we're going to go to a couple of slides here.

其中第一项技巧就是节奏,因此我们现在就要看看,我想我们要关灯,因为我们将要看组幻灯片

耶鲁公开课 - 聆听音乐课程节选

You know, it's the same father who taught me to turn off lights when I left a room.

CNN: Clinton's October 9, 2007 speech on retirement security

Sensors automatically turn off lights after five minutes if they detect no movement and adjust the light level according to the available daylight.

CNN: Catalog company going lean and green

But after a day of being urged to recycle, turn off lights and trade in our cars for bikes, the question that everybody is asking is will it make a difference?

BBC: Snoop Dogg