A.Cu+2AgN03=Cu(N03)2+2Ag B.2Al+3H2S04=Al2(S04)3+3H2t C.2Mg+C0 D.2Na202+2C02=2Na2C03+02
A.S02 B.N02 C.N2 D.NH3
A.C3H70H B.CH4 C.C2H6 D.C3H8