1. you must sign the form twice ->................... 2. visitors to the zoo mustn't feed the animals ->......... 3. all passengers must wear seat-belts ->................. 4. somebody should pick the visitors up from the airport ->...................... 5. it ín't neccessary for jim to take the exam again (need )->....... chuyễn sang passive voice

1. The form must be signed twice.

2. The animals mustn't be fed by visitors to the zoo.

3. Seat-belts must be worn by all passengers.

4. The visitors should be picked up from the airport.

5. Jim needn't take the exam again.

1. The form must be signed twice.

2. The animals musn't be fed by visitors to the zoo.

3. Seat-belts must be worn by all passengers.

4. The visitors should be picked up from the airport.

5. Jim doesn't need take the exam again.