Across
- 3. to use again
- 5. a junkyard/dump
- 7. your surroundings
- 8. help from the sun
- 10. animals living space
- 12. make something unclean
- 13. the natural home
- 15. derived from living matter
- 16. fertilizer for soil
- 17. capable on being renewed
Down
- 1. trashing everywhere
- 2. discharge of gas
- 4. protect from harm
- 6. a colorless gas
- 9. consistency
- 10. no longer on earth
- 11. the air around you
- 12. to keep safe
- 14. reuse
- 18. natural science of relationship