| A | B |
| commute | to travel to and from work each day |
| megalopolis | a region where cities and suburbs are so close they form one urban area |
| population density | the average number of people per square mile or square kilometer |
| petrochemical | a substance such as plastic, paint, and asphalt that comes from petroleum |
| industrialization | the change from an agricultural-based economy to an industry-based economy |
| Sun Belt | another name for the South |
| mixed-crop farm | a farm that produces a variety of crops |
| recession | a downturn in business activity |
| corporate farm | a large farm that is run by an agricultural company instead of a family |
| forty-niner | one of the first miners in the California Gold Rush |
| mass transit | a system of buses and trains used for transportation |