Across
- 3. Shields earth from the sun's ultraviolet rays
- 10. A branch of biology that deals with organisms and their surroundings
- 11. Related or meaning the sun
- 12. An environment for animals or humans
- 15. A place where large amounts of organisms live
- 17. Trash
- 18. A product of gas or radiation
- 19. To protect something so it lasts
- 20. Something that can be used more than once
Down
- 1. Disposing of waste and trash
- 2. Rotting organic material to be used as plant fertilizer
- 4. Surroundings that living creatures and grow and sustain themselves in
- 5. A species of animal that has been wiped out
- 6. To reuse an item and is better value than what it once was
- 7. turning trash into reusable material
- 8. Contaminated air, water or, a place
- 9. To be maintained
- 13. To keep something as it is
- 14. An envelope of gasses that encircle the planet
- 16. Something that lives and can decompose