1.Letters are typed in the office by Mary.
2.You will be helped by his father tomorrow.
3.Human life has been completely changed by science and technology.
4.This bottle was broken by Peter.
5.English are being learned in the room.
6.My mind can be changed by nothing.
7.I hadn't been told about it.
8.Her telephone number isnt known by me.
9.The children will be brought to home by my student.
10.A present was sent to me last week.
