1) The Amazon Rainforest, located in South America, is the largest tropical rainforest in the world, covering an area of approximately 5.5 million square kilometers (2.1 million square miles). It is known for its exceptional biodiversity and plays a crucial role in the global ecosystem.

2) The ancient city of Athens, Greece, is often considered the birthplace of democracy, where citizens had a say in the decision-making process.

3) Dwayne "The Rock" Johnson is an American actor, producer, and former professional wrestler. He has become one of the highest-paid actors in Hollywood, known for his roles in films such as the "Fast & Furious" franchise, "Jumanji," and "Moana."

4) International relations encompass the study of relationships between nations, including diplomacy, treaties, and foreign policy. It examines the interactions and dynamics among different countries in the global arena.