15. The farmer had put down some rat A. poisoning B. poisoner C. poisoned 16. loss can be caused by noise pollution. B. hearing C. listening A. sound 17. The government has come A. up to B. up with come up with : đến với 18. If the air was clean, we A. wouldn't 19. If he A. will throw 20. If it rains, we A. cancel 21. If I were a tree, I B. won't have to wear masks when going out. C. would D. will trash around his garden, the garden would look very nice now. B. would throw C. didn't throw D. doesn't throw the match. B. will cancel D. audio a solution to the water problems of the city. C. to with D. on to the D. poison C. cancelled rain. 2 D. cancelling