Across
- 4. A sugar
- 5. This subject
- 7. A process whereby plants turn carbon dioxide into water
- 8. A rock formed through intense heat and pressure
- 9. Top layer of the earth
Down
- 1. One of the 4 spheres
- 2. What we need to survive
- 3. The layer that protects us from meteors
- 6. A sedimentary
- 8. A planet