What must we do?    

What do you know about fire?    

What mustn't we do at home?   

What time do you go to bed?    

How do we use water?  

A. We use water to wash clothes.

B. We must be quiet.

C. We mustn't play near fires.

D. Fire gives us heat and light.

E. I go to bed at 10:00 p.m.