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

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

3) The longest-running TV show in history is "The Simpsons," which has been on the air since 1989 and has over 700 episodes.

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