| A | B |
|---|
| megalopolis | a very large city; a region made up of several large cities and their surrounding areas, considered to be a single urban complex |
| mangrove | a tropical tree that grows in swampy ground along coastal areas |
| bayou | a marshy inlet or outlet of a lake or a river |
| fall line | imaginary line between the Appalachian Mountains and the Atlantic coastal plain, where rivers and streams form waterfalls and rapids as they descend from higher elevations to the coastal plain |
| Sunbelt | the southern and southwestern states of the United States, from the Carolinas to southern California, characterized by a warm climate and, recently, rapid population growth |
| humus | the organic material that results when plants and animals that live in the soil die and decay |
| growing season | in farming, the average number of days between the last frost of spring and the first frost of fall |
| grain elevator | a tall building equipped with machinery for loading, cleaning, storing, and discharging grain |
| grain exchange | a place where grain is brought and sold as a commodity |
| tundra | a region where temperatures are always cool or cold and only specialized plants can grow |
| aqueduct | a large pipe or channel designed to transport water from a remote source over a long distance |
