In what area did airplanes first prove to be of practical value?
a.) stunt shows
b.) mail delivery
c.) the tourism industry
d.) military operations

What is the impact of enlightenment ideals on the development of economic, political, and religious structures in the western world?

On a production possibility curve, data points that fall outside of the curve represent an inefficient allocation of resources. a balanced allocation of resources. ideal production. a currently unattainable production.

What does it mean to say the united states has a federal system of government