1) The Cuban Missile Crisis in 1962 brought the United States and the Soviet Union to the brink of nuclear war during the Cold War.

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

3) The English alphabet has five vowels: A, E, I, O, and U.

4) The World Wide Web, developed by Tim Berners-Lee in 1989, revolutionized the way information is accessed and shared on the internet.