v. 用尽( exhaust的第三人称单数 ); 使非常疲倦; 详尽讨论（或研究）; 弄空

n gases ejected from an engine as waste products

n system consisting of the parts of an engine through which burned gases or steam are discharged

v wear out completely

v use up (resources or materials)

v deplete

v use up the whole supply of

v eliminate (a substance)