1) The word "telephone" contains five vowels: E, E, O, E, and E.

2) The concept of insurance dates back to ancient times when merchants would distribute their goods across different ships to reduce the risk of losing everything in a single event.

3) Bats are the only mammals capable of sustained flight.

4) The Mona Lisa, painted by Leonardo da Vinci, is one of the most famous and valuable artworks in the world.