解:
下列各组物质中,分类完全正确的一组是( )
选项
酸
碱
盐
氧化物
A
H2SO4
Ba(OH)2
H2S
H2O2
B
NaHCO3
Cu2(OH)2CO3
KCl
CO
C
HNO3
NaOH
CaCO3
CuO
D
HCl
Na2CO3
CuSO4
MnO2
– ________ of us think the English examination was difficult.
– But I still don't think ________ could pass it.