My brother usually ___ his classroom after school. But now he ___ basketball.

A．cleans; plays

B．is cleaning; plays

C．cleans; is playing

D．is cleaning; is playing

浮选机岗位维护、自修的项目有：（）

A、紧固及更换M30以下螺栓

B、处理槽体、给矿箱漏矿处

C、更换磨损严重的刮板叶片

D、清洗主轴轴承