You need Adobe Flash Player to listen to the pronunciations.
- water transformation: Changes made by humans to the waters of Earth that alter their physical or biological characteristics. Compare land transformation.
- weather: Temperature, precipitation, wind speed, humidity, cloud cover, and other physical conditions of the lower atmosphere at a specific place over a short period of time. Compare climate.
- wetland: An aquatic biome, the communities of which live in shallow waters that flow slowly over lands that border rivers, lakes, or ocean waters.
- white blood cell: Any of several types of cells that are part of an animal's nonspecific and specific internal defenses against pathogens.
- wood: A series of layers of secondary xylem. Each new layer forms a ring around the previous year's layer, producing the "tree rings" that can be used to age a tree.