1) Oprah Winfrey is an American media mogul, television host, actress, and philanthropist. She is best known for hosting "The Oprah Winfrey Show," which became the highest-rated talk show in TV history, and for her influential role in the entertainment industry.

2) Antarctica is the coldest, driest, and windiest continent on Earth. It is also the highest, with an average elevation of about 7,545 feet (2,300 meters).

3) George Clooney is an American actor, filmmaker, and activist. He gained fame for his role in the television series "ER" and has since starred in successful films such as the "Ocean's" trilogy, "Syriana," and "Up in the Air," winning several awards for his performances.

4) The Berlin Conference in 1884-1885 divided Africa among European powers and set the stage for the colonization of the continent.