Across
- 4. A change in the natural conditions of the Earth
- 5. Only planet in the solar system that has life
- 8. The primary element in all life
- 10. Its usually cold up in the _______
- 11. Plant life
- 12. Earth would not be habitable without it
- 13. There are many trees here
Down
- 1. Animal Kingdom
- 2. A layer of gas surrounding the atmosphere
- 3. Life needs this to survive
- 6. This is responsible for almost 75% of oxygen on Earth
- 7. Orangutans, rhinoceros, and blue whales are all _________ species
- 9. Living underwater rocks