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

2) The deepest part of the ocean is the Mariana Trench, reaching a depth of about 36,070 feet (10,994 meters).

3) The blue whale is the largest animal to have ever existed, with an average length of about 82 feet (25 meters).

4) The United Nations (UN) is an international organization founded in 1945 with the goal of promoting peace, security, and cooperation among nations through diplomatic and political means.