Across
- 2. Which is the closest planet to the sun
- 4. Earth is surrounded by laeyrs of gases collectively called
- 7. What is the hardest natural substance on Earth
- 8. Which is the largest planet in the solar system
- 10. What part of the skeletal system protects the brain?
Down
- 1. What are animals which eat both plants and animals called
- 3. helps pump blood through the entire body
- 5. What is Earth's only natural satellite
- 6. Similar body cells group together to form a
- 9. Dark rain clouds can give out lightning and