阀门的基本参数有公称通径、公称压力、温度-压力等级、适用介质。
参考答案：对
The new chairman was quite familiar with the for conducting a meeting.
A．question
B．people
C．procedure
D．problem
水：龙头
A．电：电线
B．电：开关
C．电：发电
D．电：电灯
