情景交际，补全对话。

A: __1__ do you usually__2__  on weekends?

B: I usually play__3__ violin.

A: What's you __4__  sport?  

B: I like__5__  football best.

A: __6__ __7__  do you play it?

B: Three __8__ a week.

A: Who do you often play __9__ ?

B: My friends. How __10__  you?

A: ...

（）吊在车底架下部，其内部有活塞、皮碗、活塞杆及缓解弹簧等。

A.空气压缩机

B.制动缸

C.总风缸

D.三通阀