Answer please and thank you

What principle did president truman invoke in sending u.s. troops into south korea without first asking congress to declare war?

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.

The viceroy of spain asked that coronado's expadition be cristian and apostolic and not a buchery,what does that mean and did cornado follow his orders