1) The word "cheese" contains three vowels: E, E, and E.

2) The concept of sovereignty refers to the supreme authority and power of a state to govern itself, make decisions, and control its own territory without interference from external forces.

3) The Great Barrier Reef in Australia is the largest coral reef system in the world and is visible from space.

4) Hugh Jackman is an Australian actor, singer, and producer best known for his portrayal of Wolverine in the "X-Men" film series. He has also starred in musicals such as "Les Misérables" and "The Greatest Showman" and has received critical acclaim for his performances.