The cataracts kept lower Egypt from coming up the Nile to trade. It made trade decline between the two.
If this is sociology, then the answer is that in any crowd, anywhere in the world, people have many different motivations.
Hope this helps, GOD BLESS! :-)
I believe the answer is: They are based on the arbitrary borders of old European empires
African continent was colonized by different european empire. To avoid conflicts among the european, they divided africa into several territories and dtermine which country has the jurisdiction over each territories. After African nations gained independence, they still use this separation as borders to differentiate one country with another.
Chinese characters use logographic script
This means that is is Difficult
Answer:
I guess you could say "120 people were interviewed in three social classes by me"
