1) The Treaty of Versailles, signed in 1919, officially ended World War I and imposed heavy penalties and reparations on Germany.

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

3) Ryan Reynolds is a Canadian actor, producer, and entrepreneur known for his roles in films such as "Deadpool," "The Proposal," and "Detective Pikachu." He has gained recognition for his comedic timing and charismatic performances on-screen.

4) 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.