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

2) The first photograph of a black hole was captured in 2019 using a network of telescopes around the world.

3) The Tour de France, first held in 1903, is one of the most prestigious and grueling cycling races, covering over 3,500 kilometers (2,200 miles) in three weeks.

4) The word "flower" contains two vowels: O and E.