When did the byzantine empire fall?

Idon't really understand the question. it counts for 20% of my lesson grade and i really need putting the answer into words. anything will . i need asap so im awarding 30 points.a disagreement between states of the united states concerning the rights of states vs. the authority of the national government led to the civil war. state governments were forced by war into a subservient position. what might happen if national governments ceded their authority to a world government by international treaty?

Which term best describes the progressive era

Considering the benefits and drawbacks of the different types of money as well as the gold standard, do you agree or disagree with the us government’s decision to discontinue the gold standard? justify your response.