Which of these was a cause of the Civil War? O the discovery of gold DO O slavery O conflict with Mexico​

What does munich’s refer to in the 13 days

Which of the following are examples of limited resources on the part of consumers?

The rise of advertising in the 1920s. i am good with seeing how advertisements shape the roaring twenties and how it developed a new way of life through modern days. but i am not sure what the details of advertising in the 1920s were. if possible can you send me links (preferrably credential links) to sources that maybe show like the first company to start advertising through the radio, how advertising benefits (statistics graphs), etc.