抗心律失常药分为下列几类 （） A.钠通道阻滞药 B.N胆碱受体阻断药 C.β肾上

简述引风机电机油站的作用？

抛物线y=a（x+1）（x-3）（a≠0）的对称轴是直线______．

根据句意及首字母提示完成句子

1. He is a f_____ basketball player.

2. Look at the s_____ on the ice! How quickly she is skating!

3. Deng Yaping was the No.1 women's s_____ player.

4. We could not have the picnic b_____ of the rain.

5. Deng Yaping joined the n_____ table tennis team in 1988.

6. Deng Yaping m_____ in English and management when she was at Tsinghua University.

Which of the followings does not belong to main maneuvering facilities?（）

A.rudder

B.propeller

C.radar

D.sider thruster

水蒸汽在（）中凝结时，使混合料温度下降。