Complete the passage with the words given. harmful breathing Part 3. pollution motorbikes need is the air People need to breathe. If they don't breathe, they will die. But how (1) people breathe? If they breathe dirty air, they will have (2) animals (3) problems. Plants and clean air too. A lot of the things in our lives create (4) and factories. Dirty air gases and make the air dirty, like cars, is called "polluted air". Air (6) (5) can also make our Earth warmer. clean
