Why does it rain? This title introduces readers to the water cycle. Evaporation, precipitation, condensation, and other vocabulary words are defined. Each stage of the water cycle and why it is important to humans is explained. Graphics provide additional support. An activity to help readers understand the concept is included.

How much water is on Earth? This title introduces readers to the different places on Earth water is found. Readers will learn the differences between rivers, oceans, lakes, groundwater, and other bodies of water. Water on Earth in the form of ice is also covered. An activity to help readers understand the concept is included.