Across
- 6. conditions in which an organism lives
- 7. converting into usable material
- 9. decayed organic matter
- 10. way to create a product of high quality
- 12. ability to be maintained
- 14. branch of biology that deals with the relations of organisms
- 16. formed from oxygen with a pungent odor
- 17. having no living organisms in a species
- 18. trash on the ground
- 19. capability of being reused
Down
- 1. things derived from living matter
- 2. maintain something
- 3. gases surrounding earth
- 4. a place to dispose of trash
- 5. contamination of water and air
- 6. production of gas
- 8. biological community
- 11. protecting an environment
- 13. renewable energy
- 15. natural home of a plant