low NO低NOx燃烧lowadj.低的；少的；低落的；低声的；卑劣的；低等的adv.低地；低声地；低下地；廉价地n.低水平；低价；低谷v.哞哞叫low exhaust tower低风井low wage industry低工资产业low power density低声能密度low pressure drop低流动阻力low-voltage arc低压电弧low-salt dyeing低盐染色low-vacuum trip低真空脱扣low breaking prop低位放顶煤支架low-compression低压缩的low-speed sweep低速扫掠