1) A single bolt of lightning can heat the surrounding air to temperatures five times hotter than the surface of the sun.

2) The largest living structure on Earth is the Great Barrier Reef, spanning over 2,300 kilometers (1,400 miles) along the coast of Australia.

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

4) The novel "To Kill a Mockingbird" by Harper Lee has been translated into more than 40 languages and has sold over 40 million copies worldwide.