Across
- 2. found in cells
- 4. humans survive by breathing it
- 9. earths surface
- 10. it is reused
- 11. water on the earths surface
- 16. prevailing weather conditions
- 17. A member of a large group of unicellular microorganisms lacking organelles
- 19. hot ball of fire
Down
- 1. a liquid substance
- 3. remains of a living thing
- 5. important natural cycle
- 6. particular air
- 7. humans live on it
- 8. the four seasons
- 12. an individual
- 13. its an important part of the atmosphere
- 14. a living thing other than a human being
- 15. where plants grow and animals live
- 18. found in all living things