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

2) The world's largest volcano, Mauna Loa in Hawaii, is also one of the most active. It stands over 13,000 feet (4,000 meters) above sea level.

3) The hibiscus flower is commonly associated with tropical regions and is the national flower of several countries, including Malaysia, South Korea, and Haiti.

4) The game of basketball was invented by Dr. James Naismith in 1891 and has since grown into a global sport played at both amateur and professional levels.