A:铜锌原电池中铜是负极
B:用电解法精炼粗铜时粗铜作阴极
C:在镀件上电镀铜时可用金属铜作阳极
D:电解稀硫酸制H2、O2时铜作阳极
—Yes. I ________there for half a month last summer holiday.
24÷38= 64
若m、n满足|m﹣2|+(n+3)2=0,则nm的值为( )