Chuyển thành câu bị động 1. A sudden increase in water pressure may not break the pipe 2. We must not take good care of books borrowed from the library 3. The man did not tell me about the news 4. We can not find him at home every time we want 5. He does not use milk for making butter and cheese 6. We have not completely changed our life and environment 7. John does not often visit Mr. Cole at weekends 8. Sam and Phi did not buy a new fishing rod yesterday 9. They were not watching TV at 9.00 last night 10. I did not plant many trees along this street last week 11. He is not going to make some plans for his summer holiday 12. No one knows him because he is too famous 13. Hung does not write two letters for his friends every month