9th-geography 1. atmospheric-pressure-and-winds 2. composition-and-structure-of-the-atmosphere-2 3. denudation 4. earth-as-a-planet 5. earths-structure 6. earthquakes 7. effects-of-pollution 8. humidity 9. geographic-grid-latitudes-and-longitudes 10. hydrosphere 11. insolation 12 landforms-of-the-earth 13. natural-regions-of-the-world 14. pollution 15. preventive-measures 16. rocks 17. rotation-and-revolution 18. sources-of-pollution 19. volacanoes 20. weathering