A system or device for doing work, as an automobile or a jackhammer, together with its power source and auxiliary equipment.
机械系统用来工作的系统或装置，如汽车或手持式凿岩机，包括其动力源和辅助设备
jackhammer详细解释
jack.ham.mer n.（名词）A hand-held machine for drilling rock and breaking up pavement, operated by compressed air.手提钻，轻型凿岩机：通过压缩空气运转的钻岩石、挖隧道的手持机器 【引伸】 jack.ham.mer v.（动词）
