USAGE NOTE 用法说明: machine
Compare 比较 machine, appliance, tool, instrument, device, and 和 gadget.
A machine usually uses power, and you do not work it directly with your hands. machine 一般用动力，不直接用手操作:
the machines in the factory 工厂里的机器
Tickets are available from the machine on the platform. 车票可以在站台上的自动售票机买到。
a knitting machine 编织机
Electrical machines used in the home (such as washing machines) can also be called appliances. 家用电器（如洗衣机）也可称为 appliances:
a shop selling household appliances 卖家用电器的商店
A tool is an object which you hold in your hand and which you use for making things from wood, metal, or other materials. tool 是拿在手中的工具，用来把木料、金属或其他材料做成各种东西:
carpenter's tools such as hammers, drills, and saws 木匠的工具，如锤、钻和锯
An instrument is an object which you use to do very exact or careful work, usually by hand. instrument 是指用来做很精细的工作的仪器，常用手操作:
medical/surgical instruments 医疗/外科手术器械
A thermometer is an instrument for measuring temperature. 温度计是测量温度的仪器。
Device is a general word for any object which has been produced for doing work, and is usually used when there is no particular word for that thing. device 是一个通用词，指制造出来供人干活用的某种装置。当没有合适的特定用词时常用这个词:
An electronic device controls the opening of the doors. 一种电子装置控制着开门。
I have no idea how this device works. 我不知道这仪器怎样操作。
Gadget is an informal word for a small and perhaps unusual device for doing a particular job. gadget 是非正式用词，指小的并且可能不平常的器具，用来做某种特殊工作:
a clever little gadget for opening bottles 小巧的开瓶器