Across
- 3. to not waste electricity
- 6. to look for sth
- 8. to cover a place with water
- 9. to no longer have sth
- 12. a flat part of land usually below sea level
- 14. to die under the water because you cannot breathe
- 15. switch off the lights
- 18. to become liquid because of heating
- 19. the action of making the air dirty
- 20. make less
- 21. to become higher in level
- 22. a repeating change in weather conditions
Down
- 1. the level of hotness or coldness
- 2. to no longer exist or be seen
- 4. the large areas of ice at the polar regions
- 5. an increase in the world's temperature due to pollution
- 7. the plants we grow to eat don't grow properly
- 10. to make or become larger;add to
- 11. to become part of sth
- 13. in place of
- 16. height, position
- 17. a long period without rain