Having become famous, Wang Baoqiang often has people ______ him in the street and ______ for his autograph (签名).

A．stopping, asking

B．stop, ask

C．stopping, to ask

D．to stop, asking

清管器进球筒后，全开干线进气阀，全关（）。

A.生产气阀

B.旁通阀

C.放空阀

D.球阀