1) The Great Barrier Reef in Australia is the largest living structure on Earth and can be seen from space.

2) The sunflower is not a single flower but a cluster of small flowers arranged in a spiral pattern.

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

4) The Treaty of Versailles, signed in 1919, officially ended World War I and imposed heavy penalties and reparations on Germany.