đề bài change following sentences into passive voice using modal verbs 1. you should open the wine about three hours before you it 2.you must not hammer nails into the walls without permission 3. people must not leave bicycles in the hall 4.member can keep books for three week 5.people should send their complaints to the main office 6.you must turn off all the switches before leaving the room 7.you must make an appointment in advance 8.someone might steal the car 9.you must keep the room tidy 10.they can't solve the problem 11.we can't restore the picture 12.you should finish all your work now 13.we have to clean the floor

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1. The wine should be opened 3 hours before it is used.

2. Nails mustn't be hammered into the walls without permission.

3. Bicycles must not be left in the hall.

4. Books can be kept by members for three weeks.

5. Their complaints should be sent to the head office.

6. All the switches must be turned off before you leave the room.

7. An appointment must be made in advance.

8. The car might be stolen.

9. The room must be kept tidy.

10. The problem can't be solved by them.

11. The picture can't be restored by us.

12. All your work should be finished now.

13. The floor has to be cleaned.

1. The wine should be opened about three hours before you use it. 

2. Nails mustn't be hammered into the walls without permission.

3. Bicycles mustn't be left in the hall.

4. Books can be kept (by members for three weeks).

5. Their complaints should be sent to the head office.

6. All the switches must be turned off before leaving the room.

7. An appointment must be made in advance.

8. The car might be stolen.

9. The room must be kept tidy.

10. The problem can't be solved.

11. The picture can't be restored.

12. All your work should be finished now.

13. The floor has to be cleaned.