按要求改写句子。

1.The students have no classes on Sunday. (改为反意疑问句)

   _______________________________________________________?

2. Is your son showing his friends the photos now? (用often代替now) 

   _______________________________________________________?

3. Would you like juice or coffee? (改为同义句)

    _______________________________________________________？

4. What does your mother want you to do? (用make cakes作答) 

    _______________________________________________________.

急救物品完好率属于（）

A．反馈控制

B．前馈控制

C．同期控制

D．预防控制

E．遥控控制