Tìm lỗi sai và sửa lại 31. The air is polluting by smoke from factories. ..................................................................................................... 32. Recycled things can be use again. ..................................................................................................... 33. This tractor used to plough the . ..................................................................................................... 34. My motorbike needs to fix. ..................................................................................................... 34. The is polarizing by smoke from factories. ..................................................................................................... 35. Millions of newspapers and paper bags are throwing away every day. ..................................................................................................... 36. For every ton of recycled newsprint, nearly ten trees can save. ..................................................................................................... 37. Books published by Kim Dong publisher are selling out so quickly. ..................................................................................................... 38. The children attracted by the circus show. ..................................................................................................... 39. We are going to a meeting holding by the Y 8:. Y club. ..................................................................................................... 40. Waste paper and old clothes will collect for our mini-project. .....................................................................................................