题目

The question nowshould be solved as quickly as we can. 答案：【1】under debate空气的净化问题正日益受到人们的关注．下列各组中成分均属于空气污染物的一组是（　　）A．SO2 CO NO2B．CO2 　HCl N2C．CH4 CO2 H2D．SO2 　N2 　O2