The system known as "triangular trade" involved

The triangular trade conducted between the three ports or regions engaged in transporting goods. The countries involved in the trade: America, Europe, and Africa. The trade opened new markets and formed a mercantile system with transporting raw materials and manufacturing goods from one port to another. Slavery, for the first time, became part of the trade and led at the beginning of the slave trade.

an earnest tone.

because portia wants to know why brutus has been acting strange lately.

islam spread slowly through much of africa through trade and preaching.