关于Cu与Cu²⁺说法不正确的是（　　）

A．Cu²⁺和Cu都属于铜元素

B．质量相差很大

C．Cu²⁺和Cu核外电子排布相同

D．Cu²⁺得到2个电子后能变为Cu

The man _____ was a friend of mine. [ ]

A. you just talked to

B. whom you just talked to him

C. who you just talked to him

D. which you just talked to