Across
- 5. the gases surrounding the earth
- 6. support and highly encourage
- 10. the ability to be maintained at a certain level or rate
- 12. gas that composes 78% f the earth's atmosphere
Down
- 1. keep safe from injury or harm
- 2. 70% of it is full of water
- 3. trees take it in
- 4. bring back or re-establish
- 7. humans depend on it to live
- 8. when the sun goes down
- 9. the number of the goal of life on land
- 11. when the sun comes up