1) A group of flamingos is called a "flamboyance."

2) The Great Wall of China is a UNESCO World Heritage site and one of the most iconic man-made structures in the world. It stretches over 21,196 kilometers (13,171 miles) and was constructed to protect the Chinese empire from invasions during ancient times.

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

4) The word "orange" contains three vowels: O, A, and E.