Across
- 2. a difference from the normal or expected
- 4. how often something happens
- 6. a system of written symbols
- 8. something that can be used to help
- 10. the special words used in a subject
- 11. something that can change
- 13. the order of events in time
- 15. the force that keeps something moving
- 16. very dry with little or no rain
- 17. something passed down from the past
- 19. a set of rules or procedures
- 20. the variety of living things in an area
Down
- 1. the authority to make legal decisions
- 3. a goal or something you aim to achieve
- 5. a community of living things and their environment
- 7. a new idea or method
- 9. a model or imitation of a real situation
- 12. an observable event or fact
- 14. the natural home of a plant or animal
- 18. something that causes change or speeds it up