Living in the dormitory means _____to take care of yourself, understand each others ' differences and share _____ interests.

A．to learn, common.

B．learning, ordinary

C．to learn, ordinary

D．learning, common

我们使用的-48V蓄电池组通常采用（）接地。

A、负极

B、负极或正极

C、正极

D、其他