The Columbian exchange, also known as the Columbian interchange, named for Christopher Columbus, was the widespread transfer of plants, animals, culture, human populations, technology, diseases, and ideas between the Americas, West Africa, and the Old World in the 15th and 16th centuries.
The letter a is the answer
Answer:The system of checks and balances is an important part of the Constitution. With checks and balances, each of the three branches of government can limit the powers of the others. Each branch “checks” the power of the other branches to make sure that the power is balanced between them.
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