What values in the american character seems to be portrayed by contemporary opinion-makers at the time of the mexican war?

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.

How does a comet change when it comes close to the sun

Which physical subsystem includes the air we breathe