What did khubilai khan need to build in order to conquer the southern song?
a. a bridge

b. cannons

c. catapults

d. a fleet of ships

How did cultural change create social conflict?

Nationalism led to major conflicts following world war i, especially when:

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.