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a large, level area that rises above the surrounding land; has at least one side with a steep slope


the height of land above sea level


a deep crack in Earth's surface


a river or stream that flows into a larger river


rich in the substances plants need to grow well


to supply with water through a ditch, pipe, channel, or sprinkler


a long period of little or no rain


a fertile place in a desert where there is water and vegetation


a region of tall grasses with scattered trees


a person who has no permanent, settled home and who instead moves from place to place

subsistence farming

raising just enough crops to support one's family

cash crop

a crop that is raised for sale


a system for producing, distributing, consuming, and owing goods and services


to add variety to; to expand a country's economy by increasing the variety of goods produced

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