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

2) The shortest war in history lasted only 38 to 45 minutes between Britain and Zanzibar in 1896.

3) The world's most expensive car is the Bugatti La Voiture Noire, which sold for over $18 million.

4) The concept of civil rights pertains to the rights and freedoms that individuals possess as members of a society, including equality before the law, freedom of expression, and protection against discrimination.