Here were the choices on that question:
a. poverty
b. lack of adequate rivers
c. mountains
<span>d. richness
The answer is D. richness. Based on A Companion to World History, the African Sahel can be a corridor of communication between Nile and Niger valleys but did not materialize. The reason was the richness of Sahel that it that it can provide for itself even without trade.
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The only solution to this problem is to say that the per capita GDP is higher for citizens in Chile than Brazil.
It makes sense cause the higher the capita the higher the growth rate is.
What are the answer choices?
I believe the correct answer would be (b)
After its main sequence a medium sized star like our sun becomes a red giant, it grows a lot bigger that it's regular size that it will burn earth into ciders, after that it will eject its own nebula and fade away as a dwarf star.