Did west africa merchants spread the black plague?

As a result of the columbian exchange, which crop was transferred to europe from the americas and later spread through the world? a coffee b maize (corn) c rice d olives e wheat

How did the phillips brothers expand their businesses? by selling it to other businessmen by changing their source product by merging their companies by acquiring government support

Humans during the paleolithic era used fire for each of the following purposes except a. for cooking meat b. for use as a weapon c. for heat and warmth d. for treating animal hides select the best answer from the choices provided