Help please!! its a history assignment

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.

Persons or group opposing or hostile to another person or group the definition word is

What did this mean for dred scott? a.scott was not a citizen of the united states. b.scott was the property of the federal government. c.scott had no right to sue for his freedom in court. d.scott was considered the property of the slaveholding family.