B: All Native Americans had been removed from the western frontier :) Hope that helped
dababy ..............................................
If an important resource, such as oil, becomes unavailable, the production possibilities curve a. shift inwards.
"The production possibility frontier (PPF) is a curve on a graph that depicts the possible amount that can be produced or made of two products, if both are based upon the same limited resource for their creation. The Production Possibility Frontier is also termed as the production possibility curve. If it shifts inwards, it means the economy is shrinking due to a collapse in issuing resources and production capacity."
"The production possibility curve (PPC )is necessary because it helps in indicating the maximum possible production of items , in fixed resources. In macroeconomics, economists study and support a country or other organization's economic activity with its help."
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Answer:
The terraces were built to make the most efficient use of shallow soil and to enable irrigation of crops by allowing runoff to occur through the outlet. The Inca built on these, developing a system of canals, aqueducts, and Iquitos to direct water through dry land and increase fertility levels and growth.
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