1) The Super Bowl is the championship game of the National Football League (NFL) in the United States and is one of the most-watched television events each year.

2) Celtic mythology encompasses the folklore and legends of the Celtic peoples across Europe, particularly in regions like Ireland, Scotland, and Wales. It features deities like Morrigan, Cernunnos, and Brigid, and delves into themes of nature, magic, and the heroic exploits of legendary figures like Cu Chulainn.

3) The Mongol Empire, under the leadership of Genghis Khan, became the largest contiguous empire in history, spanning from Asia to Europe.

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