Across
- 4. Saving resources and using them wisely
- 5. Remains of past living things
- 7. Lines that run east to west
- 8. Outer layer of Earth
- 10. Goals a design must meet
- 12. Harmful substances in the environment
- 15. Low land between mountains or hills
- 16. Moving sediment from one place to another
- 17. Moving parts of Earth that cause earthquakes
- 20. Breaking down rocks into smaller pieces
Down
- 1. Forces that build up land
- 2. Help us find places
- 3. A limit in designing a solution
- 6. Long-term changes in Earth’s weather
- 9. Caused by moving Earth’s plates
- 11. A model used to test an idea
- 13. Natural features like mountains and valleys
- 14. Energy from sources like sun and wind
- 18. Imaginary line dividing Earth into halves
- 19. When materials are dropped