Why is a convection necessary? What demonstrates that such a convection is necessary?

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 product would have been most likely to have been traded in this area at this time?

In the early 1800s, north africa was different from southern africa in that