Across
- 2. largest country in the world
- 3. syrup-producing tree
- 4. egg-laying mammal
- 5. month of christmas
- 11. air around the Earth
- 12. inverse of multiplication
- 14. first element
- 16. the science of the Earth
- 17. percussion instrument with keys
- 18. women's history month
Down
- 1. measure of temperature
- 3. the study of numbers
- 6. planet beyond Earth
- 7. currency of England
- 8. spiny little mammal
- 9. king of Olympus
- 10. possible democratic candidate
- 13. an apple fell on his head
- 15. most northern state in the U.S.