Letters are typed in the office by Mary.
You'll be helped by his father tomorrow.
The human life has completely been changed with science and technology.
This bottle was broken by Peter.
English is being learnt in the room.

6. My mind can't change.
7. I hadn't been told about it.
8. Her phonenumber isn't known (by me)
9. The children home will be brung by my students.
10. I was sent a present (by them) last week.

1. Mary types letters in the office. ->Letters are typed in the office by Mary.
2. His father will help you tomorrow ->You will be helped by his father tomorrow.
3. Science and technology have completely changed human life. ->Human life have completely been changed with science and technology.
4. Peter broke this bottle. ->This bottle was broke by Peter.
5. They are learning English in the room. ->English is being learned in the room.
6. Nothing can change my mind. ->My mind can't be changed.
7. No one had told me about it. ->I hadn’t been told about it.
8. I don't know her phonenumber. ->Her telephone number isn’t known.
9. My students will bring the children home. ->The children will be brought home by my students.
10. They sent me a present last week. ->I was sent a present last week.

1. Mary types letters in the office. ->Letters are typed in the office by Mary.
2. His father will help you tomorrow ->You will be helped by his father tomorrow.
3. Science and technology have completely changed human life. ->Human life have completely been changed with science and technology.
4. Peter broke this bottle. ->This bottle was broke by Peter.
5. They are learning English in the room. ->English is being learned in the room.
6. Nothing can change my mind. ->My mind can't be changed.
7. No one had told me about it. ->I hadn’t been told about it.
8. I don't know her phonenumber. ->Her telephone number isn’t known.
9. My students will bring the children home. ->The children will be brought home by my students.
10. They sent me a present last week. ->I was sent a present last week.