Unit 4

2. to make something smaller or less in size, amount, or price
3. to make something better, or to become better
7. when paper,glass, plastic, etc., are put througha process so that it can be used again
10. dirty air
11. things that people have thrown away and left on the ground in a public
13. smoke from cars
15. the air around a place

1. to tell sb that you will definitely do or not do sth
4. a thick forest in tropical parts of the world that have a lot of rain
5. the nature world
6. a building where goods are made
8. to find a way of dealing with a problem or difficult situation
9. unwanted things or waste material such as used paper, empty cans and bottles, and waste food
12. a long line of cars on a road that cannot move or can only move very slowly
14. to increase in number, amount, or value