Срочно, пассивный залог 3

Transform the sentences into the passive voice.
III. Present, Past, Future Perfect:
1. They have built a new hospital near the airport.
2. She had written only two letters by 5 o'clock.
3. By 9 o'clock we will have finished the work.
4. She has cleaned the room.
5. When you arrived, she had cooked dinner.
6. They will have built the block of flats by next month.