power switch

例句：

1. 1. The power switch is located on the wall behind the desk.
   电源开关位于桌子后面的墙上。
2. 2. He quickly switched off the lights when he entered the room.
   他一进房间就迅速关掉了灯。
3. 3.The engineer carefully tested each component of the power switch before installing it.
   工程师仔细检查了每个组件，然后才安装它。