出门前请检查电源开关,避免设备长时间运行。Chūmén qián qǐng jiǎnchá diànyuán kāiguān, bìmiǎn shèbèi cháng shíjiān yùnxíng.Before going out, please check the power switch to avoid leaving the equipment running for a long time.
天黑了,你去按一下灯的开关。Tiān hēi le, nǐ qù àn yíxià dēng de kāiguān.It's getting dark, so go and press the light switch.
这个开关坏了,灯一直不亮。Zhège kāiguān huài le, dēng yìzhí bú liàng.This switch is broken, and the light won't come on.