What byzantine city was a wealthy center of trade that maintained the commercial links between europe and asia? ravenna rome constantinople carthage

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?

Who issued the ruling for the supreme court? dred scott roger b. taney abraham lincoln john c. calhoun

Brainliesttt !me : ) describe the event : increase in islamic extremis in the middle east