Chuyển các câu sau thành câu bị động:

Chuyển các câu sau thành câu bị động:
12. The chief engineer was instructing all the workers of the plan.

13. They can ‘t make tea with cold water.

14. Somebody has taken some of my books away.

15. They will hold the meeting before May Day.

16. They have to repair the engine of the car.