Across
- 3. to determine using reason, logic, or mathematical terms
- 7. the period of time between two events
- 9. complete and not broken or damaged
- 10. similar in every detail; exactly alike
- 12. the line where the earth and sky seem to meet
- 13. to cause problems and prevent something from continuing in its usual way
- 14. the main and largest part of something
- 16. to follow something from its origin
- 17. to suddenly disappear
- 18. to spread over or cover a large area of land
- 19. approximately or about; not exactly
Down
- 1. when someone sails a ship over areas of water
- 2. difficult to deal with
- 4. spread over a wide area
- 5. a person related to someone from an earlier generation
- 6. a piece of information that helps you solve a problem
- 7. extremely large
- 8. the speed at which something happens; or the number of times it happens in a particular period
- 11. similar to and able to be compared with something else
- 15. an event that can be observed and studied