Why have historians only recently solved some of the secrets of early african civilizations?

What is one reason the united states had a two party system

Which of the following best describes the outcome of the bay of pigs invasion? -it ended in a draw despite strong air support from the united states. -it was a partial success that to resolve the cuban missile crisis. -it was a success and created hostility between cuba and the soviet union. -it was a failure that was an embarrassment for the kennedy administration.

What were some of the new consumer appliances that americans could purchase in the 1920s