----- Nội dung ảnh ----- Ex3. Rewrite these sentences in the passive voice. 1. By midnight, they had recaptured all the escaped prisoners. 2. Has the school board fixed a date for the field trip? 3. Lots of people had left comments under the post. 4. We still don’t know who has caused the fire. 5. Someone has delivered these letters to the manager. 6. The teacher hasn’t assigned homework yet. 7. The robbers have taken away a huge sum of money. 8. When we returned, they hadn’t completed the work. 9. Has anyone watered the flowers? 10. How many books had he written before he died?