Across
- 1. Living creature not a plant
- 4. Essential gas for breathing
- 6. where birds fly
- 7. Thin-layer of ice
- 9. All water on Earth's surface
- 10. flowing freshwater stream
- 12. organisms that photosynthesizes
- 13. Community of living organisms
- 14. Turn into ice
- 16. Fluffy white formations in the sky
- 18. Floating mass of ice
- 19. Dense area of trees
- 20. moving ridge on water's surface
Down
- 1. Layer of gases surrounding Earth
- 2. Glaciers, ice caps, and sea ice
- 3. Air in motion
- 5. Water animal with gills
- 8. All living organisms on Earth
- 11. small creatures with six legs
- 15. small narrow river
- 17. vast body of saltwater