金属X放入CuSO4溶液中有红色物质析出、放入ZnSO4溶液中无现象。则三种金属活动性由强到弱排列的是( )
A:Zn、X、Cu
B:Cu、X、Z
C:Zn、Cu、X
D:X、Zn、Cu
下列各项表述内容正确的一项是( )
— Mr. Li will check our homework this afternoon. _______ you _______ it?
— Not yet. I'm doing it right now.
—They're friendly.