1.I may open the window.
2.Children and adults must clean their teeth twice a day. (How often…?)
3.Children must go to school. (Where…?)
4.You should keep your room tidy. (What…?)
5.They should be polite.
1 May I open the window?
2 How often must children and adults clean their teeth?
3 Where must children go?
4 What should you keep tidy?
5 Who should be polite?