Across
- 4. make things happen at the same time
- 5. study of rocks and Earth's physical structure
- 6. shapes and their properties
- 8. changes light into electricity
- 9. system includes all living things on Earth
- 13. speed of a car
- 15. light particle
- 16. exact replica of something
- 17. relationship where both parties benefit
- 18. looks the same
- 19. persist for a long time
Down
- 1. study of weather
- 2. to arrange in order
- 3. earth is the center of the universe
- 7. measure distance traveled
- 10. study of earth's landscapes and environment
- 11. events in order in which they happen
- 12. the study of living things interact with environment
- 14. a boundary or limit
- 15. object looks attractive in photographs