PLEASE ANSWER ASAP

1.) How did the east coast of Africa differentiate itself from the people/places of sub-Saharan West Africa? Give economic, cultural and social differences in East Africa and the historical reason for those differences.

2.) Name 3 geographic factors that facilitated trade in the Indian ocean and explain why those factors facilitated trade.

3.) How did the presence of large nation-states like The Abbasid Caliphate or the Tang and Song dynasties facilitate trade? Specifically, why under large nation-states do we see greater trade than under small city state type institutions?