1. Mary types letters in the office.

=> Letters are typed in the ofice by Mary.

2. His father will help you tomorrow.

=> You'll be helped by his father tomorrow.

3. Science and technology have completely changed human.

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

4. Peter broke this bottle.

=> This bottle was broken by Peter.

5. They are learning english in the room.

=> English is being learnt in the room.