Across
- 4. a central rule on which something is based
- 5. a feature of something
- 6. a low area of land between hills or mountains
- 7. a great extent or quantity
- 9. fine, dry powder, tiny particles of earth
- 11. visible features of an area of land
- 13. a particular direction
- 14. desire or be curious to know something
Down
- 1. discover or identify the presence of
- 2. a flat surface
- 3. an artificial body placed in orbit
- 8. the envelope of gases surrounding a planet
- 9. a unit of measurement
- 10. a tool for delicate or scientific work
- 12. helping to establish a fact or the truth