What are two ways geography impacted Trans-Saharan trade?

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?

What did jews use for money when jesus was around?

How were chinese immigrants treated in the late 1800s