1.be uesd in 指用于什么情况下,用于什么场合.2.be used for doing sth. 用来干……的例如：The pencil is used for drawing and writing.铅笔可以用来画画和写字.3.be used as sth.被作为……用
例句：This book can be used as a text book. 这本书可以被当作课本用.
The big table can be used as a bed. 这个大桌子可以当床用.
4.be used by sb 被某人使用 例句：The machine is used by workers.这台机器是工人们使用的. 1.be uesd in 指用于什么情况下,用于什么场合.2.be used for doing sth. 用来干……的例如：The pencil is used for drawing and writing.铅笔可以用来画画和写字.3.be used as sth.被作为……用
例句：This book can be used as a text book. 这本书可以被当作课本用.
The big table can be used as a bed. 这个大桌子可以当床用.
4.be used by sb 被某人使用 例句：The machine is used by workers.这台机器是工人们使用的.