1) The Arctic Ocean is the smallest and shallowest ocean, located at the North Pole. It is covered by sea ice for much of the year.

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

3) The Battle of Waterloo in 1815 marked the final defeat of Napoleon Bonaparte and the end of his reign as Emperor of France.

4) The book series "The Chronicles of Narnia" by C.S. Lewis has sold over 100 million copies worldwide.