Across
- 1. Water that falls from clouds on earth's surface
- 5. A star and all the planets and other objects that revolve around it
- 12. Allowing light to pass through
- 15. Everything that exists in space
- 16. The Star at the center of the Solar System
- 17. The Loudness of sound
- 18. Consumers that are eaten by predators
- 19. The condition of the atmosphere at a certain place and time
- 20. An environment that meets the needs of an organism
Down
- 2. The bending of light as it moves from one material to another
- 3. A pattern of stars that form a picture in the sky
- 4. A simple machine that consists of a wheel with a line around it
- 6. A post with threads wrapped around it
- 7. A huge ball of very hot gases in space
- 8. A large body that revolves around a star
- 9. Position of an object that change during a certain amount of time
- 10. Not allowing light to pass through
- 11. A simple machine made of two inclined planes placed back to back
- 13. A living thing such as a plant that can makes its own food
- 14. Allowing only some light to pass through