在调速系统中称为有静差调速系统的是（）。A、开环系统B、闭环系统C、单闭环系统D、双

句型转换

1. Must we drink eight cups of water every day?(作否定回答)

    No, __________ __________ __________ __________.

2. You'd better ask our computer teacher for help.(改为否定句)

    You'd better __________ __________ our computer teacher for help.

3. He talked with his father on the phone.(对画线部分提问)

    __________ did he __________ with his father?

4. His father coughs badly, so he must stop smoking. (同义句转换)

    His father has a bad cough, so he must __________ __________smoking.

5. What's wrong?(同义句转换)

     What's __________ __________?

宴会就餐应注意哪些礼仪？

加热炉瓦斯火嘴结焦的原因？

B100—50单级悬臂式离心水泵的规格是( )。

A．入口直径100mm，扬程50m水柱

B．流量100m³/h，扬程50m水柱

C．扬程100m水柱，流量50m³/h

D．扬程100m水柱，入口直径50mm

对疟疾由一定效果的抗生素是：

A．氯霉素
B．四环素
C．二者均是
D．二者均不是