1.Letters have been typed by Mary in the office.
2.You will be helped by his colleague and him tomorrow.
3.Human life has been completely changed by science and technology.
4.This photocopier was broken by Peter yesterday.
5.New staff members are being trained in the conference room.
6.My mind cannot be changed by anything.
7.I had not been told about the change in the company policies.
8.Her telephone number is unknown to me.
9.The children will be brought home by my students.