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 tomorrrow.

3, Science and technology have completely changed human life.

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

4. Peter broke this bottle.

=> This bottle is broken by Peter.

5. They are learning English in the room. 

=> English is being learnt in the room .