10. The accident was seen by MrSmith.

- BĐQKĐ: S + was/were + VPII + (by O)

11. My briefcase has been taken.

- BĐHTHT: S + have/has + been + VPII + (by O)

12. Our written work was returned to us by the teacher.

- BĐQKĐ: S + was/were + VPII + (by O)

13. The report has been finished by noon.

- BĐHTHT: S + have/has + been + VPII + (by O)

14. The little boy was bitten by the mad dog.

- BĐQKĐ: S + was/were + VPII + (by O)

15. Five suspects have been arrested by the police.

- BĐHTHT: S + have/has + been + VPII + (by O)