Sure! Here are the sentences rewritten in passive voice:

1. The bills must be paid by him before the fifth of the month.
2. That box has not been opened by anyone for the past hundred years.
3. The boy was screamed at by the boy while one of his teeth was being pulled out by the dentist.
4. Many houses have been destroyed by the fire.
5. The chairs are being carried into the house by the children.
6. He was awarded the Nobel Prize for medicine in 1946.
7. He was seen leaving the office at 6 o’clock this morning.
8. I was not allowed to go to school this morning because I was ill.
9. These plants ought to be watered by you once a week.
10. She was seen driving a car near the bridge.
11. It was thought that he had boarded the plane in New York.