A.剛玉(Al2O3) B.K2O與Na2O比值大于3.5的硅酸鹽 C.鎂質(zhì)瓷 D.K2O與Na2O比值大于1.5的硅酸鹽
A.聚四氟乙烯 B.聚氯乙烯 C.聚苯乙烯 D.酚醛樹脂
A.CO2和CO B.NO和CFC C.CH4和C2H4 D.H2O和N2H4