3. One of the main problems challenging the economics of many African nations today is
a. a lack of diverse exports
b. increasing their export of raw materials
c. competing with the industrial output of other African nations
d. making fishing more productive
I'm not sure but I think it's B.
'many African nations depend on one of two exports. If the world price drops, entire economies crumble. Thus governments are trying to diversity, or increase the variety of, their exports.'
Here are a number of sites that will help you with these questions.
http://www.google.com/search?hl=en&source=hp&ie=ISO-8859-1&q=Afrrican+nations+export+problems&btnG=Google+Search