Why did South Carolina threaten secession, and how was the crisis resolved

What were the differing views of the presidency held by the framers?

How did industrial production improvements impact export-dependent areas of the world during the great depression?   a.  demand for certain raw materials rose.      b.  demand for certain raw materials fell.      c.  the new technology was exported to most raw material producing nations.      d.  there was a decrease in tariffs.

Which form of government have the african nations had since independence?