1) The world's largest flower is the Rafflesia arnoldii, which can grow up to 3 feet (1 meter) in diameter and weighs about 15 pounds (7 kilograms).

2) The Triple Crown in horse racing consists of three prestigious races: the Kentucky Derby, the Preakness Stakes, and the Belmont Stakes.

3) The world's oldest university, Al-Qarawiyyin, was founded in 859 AD and is located in Fez, Morocco.

4) The world's first car radio was invented in 1929.