Answer;
Radio networks
Explanation;
-Magazines were america s only national medium from the 1890s until the 1920s when radio networks was/were established.
-Radio network became an accepted commercial medium during the 1920s. Initially many thought it was too intrusive a medium to allow advertising, as it entered people’s homes by the end of the decade, advertising had become an integral aspect of programming.
Water and fertile soil were Mesopotamia's<span> major resources. </span>
The easiest way to travel between the two is by boat on the Chesapeake Bay
