1. Letters are typed in the office by Mary.

2. You’ll be helped by his father tomorrow.

3. The human life has completely been changed with science and technology.

4. This bottle was broken by Peter.

5. English is being learnt in the room.

6. My mind can’t be changed.

7. I hadn’t been told about it.

8. Her telephone number isn’t known.

9. The children will be brought home by my students.

10. I was sent a present last week.

11. We were given more information.