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

i think the answer is a and i hope this ; ))

there are many ways of getting involved on your local party. attached you will find the brochure that describes some ideas: go ahead and visit your local hq, become a volunteer on your comnunity or struggle up for your own ideas so you can make them real.

the phenomenon that would be cited as evidence of increased economic interdependence between europe and the americas is  the development of mercantilism.

this theory suggests that the wealth of a country depends on its economic assets, or capital.

hope this : )

a plantation economy is an economy based on agricultural mass production, usually of a few commodity crops grown on large farms called plantations. plantation economies rely on the export of cash crops as a source of income.

i hope this : )