The sugar and rubber plantations in the Caribbean Islands and southern U.S. cotton plantations were the main source of sugar, rubber and cotton in Europe. And those were the two places most of the African slaves were sent to.
The correct answer to this open question is the following.
The African slave trade was adapted to European needs in the following ways.
European people knew that African slaves were much needed in the American plantations to produce the number of crops they needed to trade. American colonies had plenty of naturals resources due to the fertile soil in many regions that grew sugar, rice, corn, tobacco, and cotton, much needed in the European markets. So slaves made possible too much crop production in the Americas. These crops and raw materials were exported to Europe and then, Europeans exported manufactured products to the American colonies.
Alexander the greats troops refused to advance and expand their army further than the Indus river Valley. His soldiers thought he was TOO arrogant and felt like he was losing his power. He was living in Babylon for a while. Soldiers thought he was "siding with another nation".
