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) In Norse mythology, the World Tree, known as Yggdrasil, is a massive ash tree that connects the nine realms of existence. It is considered the center of the cosmos and serves as a conduit between different realms, including Asgard (realm of the gods), Midgard (realm of humans), and Helheim (realm of the dead).

3) The world's largest volcano, Mauna Loa in Hawaii, is also one of the most active. It stands over 13,000 feet (4,000 meters) above sea level.

4) Mount Everest, located in the Himalayas, is the highest mountain on Earth, reaching a peak elevation of 29,032 feet (8,848 meters).