externally operable part

例句：

1. 1. The externally operable part of the device is designed to be easily accessible for maintenance.
   该设备的可操作部分设计为易于维护。
2. 2. The externally operable part of the circuit board allows for easy connection and disconnection.
   电路板的可操作部分允许轻松连接和断开。
3. 3. The externally operable part of the machine is responsible for controlling the movement of the conveyor belt.
   机器的可操作部分负责控制输送带的运动。