1) The Federal Reserve System, often referred to as the Fed, is the central banking system of the United States.

2) In Aztec mythology, Quetzalcoatl is a prominent deity often depicted as a feathered serpent. He is associated with creation, fertility, and wind, and is considered a cultural hero and patron of priests and rulers. The arrival of Spanish conquistadors was interpreted by some as the return of Quetzalcoatl.

3) The musical "Les Misérables" is one of the longest-running shows in the West End and Broadway, with over 13,000 performances.

4) Bats are the only mammals capable of sustained flight.