Final answer:
The exchange of coffee from Africa to Asia to Europe is an example of how three continents were connected in the Columbian Exchange.
Step-by-step explanation:
An example of how three continents were connected in the Columbian Exchange is the exchange of coffee from Africa to Asia to Europe.
During the Columbian Exchange, coffee beans were introduced to Africa from Asia and then brought to Europe by the European explorers. This exchange led to the spread of coffee cultivation and consumption across the three continents.
It is important to note that there were multiple exchanges of plants, animals, and diseases during the Columbian Exchange, but the trade of coffee is one specific example of how three continents were connected.