Puzzle 1

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Across
  1. 1. A system of government where people vote
  2. 5. Shaking of the ground caused by tectonic movement
  3. 6. The layer of gases surrounding Earth
  4. 8. Reusing materials to reduce waste
  5. 12. Harmful substances added to the environment
  6. 13. When liquid water changes into gas
  7. 14. One of Earth’s large landmasses
  8. 15. A global network used for communication and information
  9. 17. The natural home of a plant or animal
  10. 18. The process of releasing energy from food
  11. 19. A tool used to find directions
  12. 20. Energy caused by moving electric charges
Down
  1. 2. An imaginary line that divides Earth into two halves
  2. 3. How hot or cold something is
  3. 4. A rocky object that orbits the Sun
  4. 7. Living and non-living things interacting in an area
  5. 9. A mountain that can erupt with lava
  6. 10. The force that pulls objects toward Earth
  7. 11. The process plants use to make food using sunlight
  8. 16. A tool used to see very small objects