Across
- 7. a particle of light
- 8. an instrument used to measure distance traveled
- 11. numerical summary of a population
- 13. a paper copy of a document or picture that is made with a special machine
- 14. science dealing with the earth's history as recorded in rocks
- 15. study of how living things interact with each other and their environment
- 17. arranged in order of time
- 19. A model of the universe in which Earth is at the center of the revolving planets and stars.
Down
- 1. mutually beneficial; supporting one another's life
- 2. part of Earth in which life exists including land, water, and air or atmosphere
- 3. the study of weather
- 4. instrument for measuring speed
- 5. to cause to happen at the same time
- 6. the study of the earth's physical and cultural features
- 9. having the same shape, size, and position on both sides of a dividing line
- 10. continuing for a long time
- 11. attractive in pictures or photographs
- 12. having a form composed of one or a number of simple shapes, such as triangles, squares, or circles
- 16. a device that converts light energy into electrical energy
- 18. arrangement of events in time