——Do you know________?

——This afternoon.

A．when will the policenman give us a talk

B．where will the policeman give us a talk

C．when the policenman give us a talk

D．where the policeman will give us a talk

地下燃气铸铁管与钢管之间的连接，宜采用法兰连接，连接螺栓宜为()。

A．不锈钢螺栓

B．合金钢螺栓

C．可锻铸铁螺栓

D．钢制螺栓