what are three things the Federal reserve does?

Answer 1

Their Mission Statement says:

.... the Federal Reserve’s duties fall into four general areas:

- conducting the nation’s monetary policy by influencing the monetary and credit conditions in the economy in pursuit of maximum employment, stable prices, and moderate long-term interest rates

- supervising and regulating banking institutions to ensure the safety and soundness of the nation’s banking and financial system and to protect the credit rights of consumers

- maintaining the stability of the financial system and containing systemic risk that may arise in financial markets

- providing financial services to depository institutions, the U.S. government, and foreign official institutions, including playing a major role in operating the nation’s payments system

....

I guess you'll have to pick three

Answer 2

Sells U.S. Treasuries when it wants to decrease the money supply.
Buys U.S. Treasuries when it wants to decrease the money supply.
Performs check clearing operations (except the very large companies usually do it themselves).

Answer 3

Prints currency and releases it at its discretion.

Mints Coinage and released it at its discretion.

Stores money.