This book has eight units: 1) The Solar System - Parts of the Solar System, A Year, Day and Night, The Seasons, etc.; 2) Weather - Clouds, Humidity, Storms, etc.; 3) Land and Water - Rivers, Lakes and Ponds, Mountains, etc.; 4) Regions of Earth - Deserts, Forests, The Arctic, etc.; 5) Shaping the Surface - Weathering and Erosion, Soil, People Change the Surface, etc.; 6) The Changing Earth - Volcanoes, Earthquakes, How Mountains are Formed, etc.; 7) Materials of Earth - Minerals, Rocks, Ores, etc.; and 8) Conservation - Saving the Soil, Keeping Air Clean, Keeping Water Clean, etc.