1. You should open the wine about three hours before you use it.
=> The wine should be opened about three hours before you use it.
2. You must not hammer nails into the walls without permission.
=> Nails mustn't be hermered into the walls without permisssion.
3. People must not leave bicycles in the hall.
=> Bicycles mustn't be left in the hall.
4. Members can keep books for three weeks.
=> Books may be kept for three weeks.
5. People should send their complaints to the main office.
=> Their complaints should be sent to the main office.
6. You must turn off all the switches before leaving the room.
=> All the switches turned off before leaving the room
7. You must make an appointment in advance.
=> An appointment must be made in advance
8. Someone might steal the car
=> The car might be stolen.
9. You must keep the room tidy.
=> The room must be kept tidy by you.
10. They can’t solve the problem.
=> The problem can't be solved by them.
11. We can’t restore the picture.
=> The pictures can't be restored
12. We can never find him at home.
=> He can never be found at home.
14. He can’t repair my new cars in the garage
=> My car can't be repaired in the garage
15. They must finish their homework before they go to bed.
Their homework must finished before go to bed