Across
- 1. the number of the world's continents
- 5. the primary source of earth's energy
- 7. the process that plants use to convert sunlight into food
- 9. animals that eat both plants and meat
- 10. an essential gas that enables humans to breathe
Down
- 2. the only planet capable of sustaining life
- 3. part of the plant that takes in water and minerals from the soil
- 4. the biggest planet in the solar system
- 6. the first element of the periodic table
- 8. the number of planets in the solar system