1) Brad Pitt is an American actor and film producer. He has starred in a wide range of films, including "Fight Club," "Inglourious Basterds," and "Once Upon a Time in Hollywood," and has received critical acclaim and numerous awards for his performances.

2) Democracy is a system of government in which power is vested in the people, who exercise it through elected representatives. It allows for political participation, freedom of speech, and protection of individual rights and liberties.

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

4) 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).