What were the Middle Ages? Why do some people refer to them as "The Dark Ages?"

How does the concept of competition relate to the arms race between the us and the soviet union during the cold war?

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.

Why do you think alexander hamilton wanted to pay back the bonds from the confederation government