1) The assassination of Archduke Franz Ferdinand of Austria in 1914 triggered the start of World War I.

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

3) The Victoria Amazonica water lily has leaves that can grow up to 10 feet (3 meters) in diameter, making it one of the largest aquatic plants.

4) The first successful mass-produced personal computer, the IBM PC, was introduced in 1981 and played a significant role in popularizing the use of computers in homes and offices.