cleansn.精煤（=clean coal）v.打扫，清扫（动词clean的第三人称单数）cleanadj.干净的；纯洁的；完全的；空白的；正当的；精准的adv.完全地n.清洁v.打扫；清扫；擦，刷clean method清洁方法clean-room洁净室cleaning oil清洗油clean player遵守比赛规则的选手clean market清洗行业clean a room打扫房间clean-bredadj.纯血种的；纯种的clean l/c[经] 光票信用证clean mining高回收率开采法,全采cleaned rice白米

1. He sniffed the fresh morning air.
   他吸进早晨的新鲜空气。
2. "A sweet temper" is a figurative expression, but "sweet coffee" is not.
   "甜蜜的性情"是个比喻的说法，而"甜咖啡"则不是。