Abook about diaries kept during the holocaust. is this a primary or secondary source? explain.

Rivalries between european imperialist powers and the growth of european militaries contributed to which outcome in the early 20th century? o a. many european powers were eager to go to war with one another. o b. european states became less concerned about controlling overseas empires. o c. small countries became more willing to join powerful empires. o d. the alliance system that maintained a balance of power in europe broke down.

How was the government that was created at the constitutional convention similar to the one proposed in the virginia plan?

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.