Please switch off the lights when you leave.

出门时请随手关灯.

《现代汉英综合大词典》

Don't leave the lights on it wastes electricity.

走时要随手关灯--以免浪费电.

辞典例句

Close the door Turn off the faucet and light when not needed.

随手关灯、关门、关水龙头,并节约用水.

互联网

Save water and electricity. Turnlight and faucet when it is not needed.

节约用水用电. 随手关灯和水龙头.

互联网

Save water and electricity . Turn off light and faucet when it is not needed.

节约用水、用电、随手关灯及水龙头.

互联网