Who is Upton Sinclair? What did he investigate?

The president has what role as the head of the armed forces 1.commander 2.general in chief 3.commander in chief 4.chief petty officer 5.joint chief

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 statement describes the impact of the 21st amendment?