A:石膏(CaSO4•2H2O)
B:硫铁矿(FeS2)
C:纯碱(NaHCO3)
D:芒硝(Na2SO4•10H2O)
A. I like this postcard.
B. Yes, I do.
C. It's rainy.
D. Sure.
E. On the left.
下列说法正确的一项是( )