"Cycles." . . . . . . . . . . . "Earth's waters" . . . "Electronic books" . . "A project guide to Earth's waters" . . "Juvenile works" . . . "Introduces basic scientific principles about water and the water cycle, providing instructions for simple experiments that examine such topics as solubility, density, the pH scale, and capillarity." . . . "Science projects." . . "Hydrologic cycle." . . . . "Water." . .