apparatus n. /instrument n. /device n. /appliance n.

apparatus主要指“器械，装置，仪器，器官”;

instrument主要指“仪器，工具，乐器”;

device指“器具，装置，仪表，手段”;

appliance指“器具，器械，家用电器等”。

例：The television men set up their apparatus, ready to film.

摄制组的人架好机器准备开拍。

All surgical instruments must be sterilized before use.

手术前，所有手术器械必须消毒。

The television receiver is an electronic device.

电视接收机是一种电子设备。

The kitchen is equipped with modern appliances.

厨房装备了现代化的炊事用具。