A:除去CO2中的CO(灼热的CuO)
B:除去O2中的H2O蒸汽(浓硫酸)
C:除去FeSO4溶液中的CuSO4(锌粉)
D:除去Cu粉中的铁粉(稀硫酸)
It's sunny today. I don't like the .
What does Jim think of his car?
计算 a÷ • 的结果是( ).