compoundn.化合物；复合词；复合物n.院子(用围墙圈起来的场地）adj.化合的；【语】（词语等）复合的；【植】复合的；【动】群体的vt.混合；调合；使严重；私了；【经】以复利计算vi.妥协compound chaos复合混沌

1. Start with the pollution most cities have, nitrogen oxides and hydrocarbons from tailpipe emissions and smokestack pollutants, mix in the heat and sunlight, and you get ozone.
   而制造污染的是汽车尾气和烟囱排出的氮氧化合物和氮氢化合物，它们在高温和阳光下混合，就会产生臭氧。