1) The Mongol Empire, under the leadership of Genghis Khan, became the largest contiguous empire in history, spanning from Asia to Europe.

2) The fall of the Berlin Wall in 1989 symbolized the end of the Cold War and the reunification of East and West Germany.

3) The name "Bluetooth" comes from the 10th-century Danish king, Harald Bluetooth, who united Denmark and Norway.

4) The most-watched TV series finale in the United States was "MAS*H," with an estimated 105 million viewers.