| A | B |
|---|
| tide | the daily rise and fall of the oceans and other bodies of water connected to the ocean |
| transportation | ways of moving people and goods |
| population density | the number of poeple live in a unit of an area |
| plateau | a large, high-level area of land |
| textile | cloth or fabric made by weaving or knitting |
| fall line | the area where rivers form water falls or rapids because of a general drop in the land's elevation |
| mass transit system | public transportation (buses, subways, etc.) that carries many people through urban and suburban areas |
| ridge | a line of hills or mountians |
| deep mining | finding and removing coal and other ores and minerals by digging underground shafts and tunnels |
| surface mining | stripping away layers of soil to uncover and remove underground seams of coal, ores, or other minerals |
| subsistence farming | growing crops or raising animals for survival, not for sale |
| barter | to trade goods or services for other goods or services |
