What was traded from the Old World to the New World?

Christopher Columbus introduced horses, sugar plants, and disease to the New World, while facilitating the introduction of New World commodities like sugar, tobacco, chocolate, and potatoes to the Old World. The process by which commodities, people, and diseases crossed the Atlantic is known as the Columbian Exchange.

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Explanation:

sumerians were responsible.

social contract theory, nearly as old as philosophy itself, is the view that persons' moral and/or political obligations are dependent upon a contract or agreement among them to form the society in which they live