That would be the Mississippi River<span />
For the history part on your question: Africa was the first continent outside of Asia that Islam spread into, in the early 7th century. It first came to Africa with Muslim refugees fleeing persecution in the Arab peninsula. This was followed by a military invasion, some seven years after the death of the prophet. Islam quickly spread west from Alexandria to pockets in Egypt, Nubia and Ethiopia.
For the impact part of your question: After the death of the Prophet, 100 years after, between the 8th and 9th centuries Arab traders and travelers began to spread the religion along the eastern coast of Africa. So, Islam impacted the continent very greatly, from the establishment of mosques to many other different factors.
I hope I helped. I just kind of did a really brief summary over what I believed was the answer. Anyway, I tried to answer your question to the best of my ability and knowledge. I'm sorry if this was not what you were looking, but I feel you can take a little something from this brief answer. Have a nice day and hope it helps :)
The correct answer is - China, India, and the United States.
China, India, and the United States are the three biggest agriculture producers in the world. The basic reason for their huge production is that all three countries have very large populations, thus lots of mouths to feed, and another reason is trade, by production and exporting agricultural goods that they can produce and are in very high demand on the global market.
The biggest percentage of the agricultural production, in all three countries falls on the basic food source they use, so for China and India it is the rise, while for the United States it is the corn.
The long term effect on the elevation of the area will be that it stays pretty much the same.
Explanation:
The isostatic uplift is a process where a land mass is gaining in height after the pressure on top of it is gone, most often because of melting of large masses of ice. The leveling is a process that occurs because of the erosion, which is destroying the physical features and gradually makes them flatter and lower.
If both of these things occur at the same place, the end result will be a relatively same elevation on the long term. The reason for that is that the elevation that is gained from one side will be getting lowered from the other side.
The answer is Khartoum, Sudan
