Airplanes first proved to be of practical value in mail delivery.
In what area did airplanes first prove to be of practical value?
(1 point)
Responses
stunt shows
mail delivery
the tourism industry
military operations
1 answer
(1 point)
Responses
stunt shows
mail delivery
the tourism industry
military operations
1 answer
Airplanes first proved to be of practical value in mail delivery.