9781422270622

WORDS TO UNDERSTAND

apprenticeship: a formal training program that combines supervised practical experience and classroom instruction; the program is free to apprentices, who receive pay that increases as they obtain experience aspiring: planning to do something, such as going to college or pursuing a specific career ozone: a naturally occurring gas—in small, trace amounts—in the upper atmosphere (the stratosphere) of Earth; ozone is created by chemical reactions between air pollutants from vehicle exhaust, gasoline vapors, and other emissions soil erosion: a naturally occurring process in which topsoil is worn away by the natural physical forces of wind and water wind turbine: a mechanical device with more than 8,000 parts that captures the energy of the wind and converts it to electricity

10