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

2) The Northern Lights, also known as the Aurora Borealis, are natural light displays that occur in the polar regions due to interactions between the Earth's magnetic field and solar particles.

3) The word "cheese" contains three vowels: E, E, and E.

4) The first successful portable MP3 player, the Diamond Rio PMP300, was released in 1998 and could hold up to 60 minutes of music.