| A | B |
|---|
| contiguous | joined together inside a common boundary |
| coral reefs | low-lying islands formed by the skeletons of small sea animals |
| megalopolis | areas in which neighboring urban areas blend into a "super city" |
| interdependent | referring to countries or people who rely on one another |
| rural | relating to the countryside, not the city |
| mobile | moving from place to place |
| multicultural | referring to something that includes many different cultures |
| urban | related to a city or densely populated area |
| ethnic group | group of people who share a common, culture, language or history |
| republic | form of government in which the people elect their own officials |
| revolution | a sudden political change |
| colony | overseas settlement tied to a parent country |
| immigrants | people who came from other lands to live in the United States |
| service industry | businesses that give services to people |
| acid rain | pollution that mixes with water vapor and falls to earth as rain or snow |
| dry farming | plowing farmland so that it holds water |
| farm belt | the productive farms of the Midwest |
| free enterprise system | people own and run businesses with limited government control |
| Mississippi River | longest river in the United States |
| Appalachian Mountains | mountain range just west of the Atlantic coastal plain |
