What were the reasons for the re-emergence of serfdom in eastern europe in the early modern period?

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.

When and why did the united states enter world war 2

In a short paragraph, explain what franklin’s attitude would be toward today’s standardized testing.