选项
被提纯的物质
杂质
除杂试剂
除杂方法
A
CO(g)
CO2(g)
NaOH 溶液、浓 H2SO4
洗气
B
Na2CO3(s)
NaHCO3(s)
——
灼烧
C
Cl2(g)
HCl(g)
饱和食盐水、浓H2SO4
D
NH4Cl(aq)
Fe3+(aq)
NaOH溶液
过滤
A:A
B:B
C:C
D:D
—Congratulations. He did well playing football when he was very young. I hope he'll be the best player in our school.
不等式组x<2m+1x<m-2的解集是x<m﹣2,则m的取值应为____
将函数y=cos2x-4π3的图像向左平移φφ>0个单位,所得图像关于y轴对称,则φ的最小值为( )