1. Somebody has taken my briefcase.

=> My briefcase has been taken.

2. The teacher returned our written work to us.

=> Our written work was returned to us by the teacher.

3. She had finished her report by soon.

=>  Her report had been finished by soon.

4. The mad dog bit the little boy.

=> The little boy was bitten by the mad dog.

5. The police have arrested five suspects.

=> Five suspects have been arrested by the police.

6. The doctor ordered him to take a long rest.

=> He was ordered to take a long rest by the doctor.

7. Lightening struck the house.

=> The house was struck by lightening.

8.A group of students have met their friends at the rail way station.

=> A group of students’ friends have been met at the rail way station.

9. They didn’t allow Tom to take these books home.

=> Tom wasn’t allowed to take these books home.