How did americans contribute to the allied victory in world war 1

Which statement best describes a major advantage of a confederal system of government over a unitary system

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 kind of relationship did the soviet union have with the united states in 1945