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How was rockefeller able to build his monopoly across the oil industry? he found newer and cheaper ways to refine oil, increasing his profits. he confined his business to ohio so he could buy all the refineries there. he bought up oil refineries, cut costs, and reinvested his profits in other refineries. he began to sell kerosene as well as oil, expanding his market.

What did the marshall plan do ? apex a.send aid to countries in europe b.sent atomic weapons to asia c.sent more ships to the pacific d.sent aid to the soviet union answer ; is a

Describe how the ways in which african americans migrated during the great migration were similar to the immigrants who arrived from other countries in the early 1900s.