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 .
1. Mary types letters in the office.
\(\rightarrow\) Letters're typed in the office by Mary.
2. His father will help you tomorrow.
\(\rightarrow\) You will be helped by his father tomorrow.
3. Science and technology have completely changed human life.
\(\rightarrow\) Human life has been completely changed by science and technology.
4. Peter broke this bottle.
\(\rightarrow\) This bottle was broken by Peter.
5. They are learning English in the room.
\(\rightarrow\) English is being learned in the room.