which situation would be more likely to occur in the modern era than in other periods of human history

Plz 50 points answer only if you know and don't copy answer describe how the geography of the korean peninsula affected where people settled and how they lived.

What was the main argument of plessy in plessy v. ferguson

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.