left adj.左边的adv.向左n.左边；左派分子；【体】左手拳动词leave的过去式和过去分词形式.
off adv.表示状态的关闭或离开prep.离开；在...之外adj.空闲的；离开的；关闭的v.离开；脱下
双语例句
用作形容词 (adj.)
You'll save electricity by turning off lights not in use. 把不用的灯关掉能省电。
So many people had those beepers attached to their belts and they took great care to expose them even when not in use,just to show off. 好多人把它别在腰带上，不用的时候也想方设法把它露出来，就是为了炫耀。
