Across
- 6. the surroundings or conditions in which a person, animal, or plant lives or operates
- 7. convert (waste) into reusable material
- 9. organic material used as a plant fertilizer
- 10. reuse (discarded objects or material) in such a way as to create a product of higher quality or value than the original
- 12. able to be maintained at a certain rate or level
- 14. the branch of biology that deals with the relations of organisms to one another and to their physical surroundings
- 16. a colorless unstable toxic gas with a pungent odor and powerful oxidizing properties, formed from oxygen by electrical discharges or ultraviolet light
- 17. having no living members; no longer in existence
- 18. trash, wastepaper, or garbage
- 19. energy derived from natural sources that are replenished at a higher rate than they are consumed
Down
- 1. relating to or derived from living matter
- 2. maintain (something) in its original or existing state
- 3. made of the layers of gases surrounding a planet or other celestial body
- 4. a place to dispose of refuse and other waste material by burying it and covering it over with soil
- 5. Contaminate
- 6. the production and discharge of something, especially gas or radiation
- 8. geographic area where plants, animals, and other organisms
- 11. Protect
- 13. relating to or determined by the sun
- 15. the natural home or environment of an animal, plant, or other organism