What made the mayan's the most sophisticated civilizations of the early americas?

Who led the continental army in the final decisive battle of the revolutionary war at yorktown

Describe two observations that galileo was the first to make with his telescope.

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.