Across
- 4. gas surronding the earth
- 6. arrangement of natural and artifical physical features
- 8. ability to be maintained at a certain level or rate
- 10. variety of plant life
- 12. the weather conditions
- 14. ecyosystem of water
- 16. the height
- 17. outer part of the earth
Down
- 1. surface and atmosphere
- 2. living
- 3. system formed by organisms
- 5. inhabitant of earth
- 7. Angular distance of North and South
- 9. combined mass of waters
- 11. occupying space
- 13. biological not living
- 15. large natural occuring community