Across
- 3. Fuel obtained from dead and decaying remains
- 9. rain containing excessive acids
- 10. naturally decomposable substances
- 12. prevention of wasting a useful resource
- 13. A place with a high density of trees
- 14. conservation of waste to usable items
- 15. artificial surroundings created for the growing of plants
- 18. a place where garbage is disposed
Down
- 1. Planting of trees
- 2. Dangerous biological substances
- 4. A person who studies about environment
- 5. The variety of life found on Earth
- 6. Introduction of contaminants into the environment
- 7. Energy generated from the heat of the sun
- 8. gradual warming of earth dues to activities of man
- 10. The natural gas formed by manure
- 11. Gas which protects us from ultraviolet rays
- 16. The physical Earth and the things in it
- 17. the branch of biology that deals with the relation of organisms