turn-off arm

例句：

1. 1.The engineer turned off the main power switch with a quick twist of the knob.
   工程师迅速扭动旋钮，关掉了主电源开关。
2. 2. The doctor used the turn-off arm to cut off the patient's oxygen supply.
   医生使用关断臂切断了患者的氧气供应。
3. 3.During maintenance, the technician had to turn off the turn-off arm to access the circuit board.
   在维护过程中，技术人员必须关闭关断臂才能接触到电路板。