Across
- 4. a colourless or odourless gas
- 9. ... is in orbit around the Sun
- 10. animals at risk of extinction
- 12. an inlet of the sea
- 14. a low area of land between hills
- 15. the use of the sun's energy
- 18. a small, narrow river.
- 19. potential, kinetic, thermal...
- 20. a high area of land
- 21. long-term shifts in weather
Down
- 1. action of making land,water,air,dirty
- 2. a tropical forest
- 3. ... is an opening in the earth's crust
- 5. a large floating mass of ice
- 6. animals growing in natural conditions
- 7. the land near a shore
- 8. water falling from a height
- 11. a natural underground chamber
- 13. sea life
- 16. All plants and animals need ...
- 17. unwanted or unusable materials
- 19. the natural world