This document is a science quiz about water and the hydrosphere. It asks questions about why water is important, how it is used, and basic facts. Water is important because many animals live in it, life began in it, and ocean water is salty. At home, water is used for drinking, cooking, cleaning, and bathing. Organisms also use water for metabolic processes like photosynthesis. The easiest sources of accessible water for human use are rivers, lakes, and ground water. Life exists on Earth because water is liquid at normal temperatures. The largest part of the graph represents the oceans, which hold the majority of Earth's water.