1) The United States operates under a two-party system, with the Democratic Party and the Republican Party being the two major political parties that compete in elections and shape the country's political landscape.

2) The fall of the Berlin Wall in 1989 symbolized the end of the Cold War and the reunification of East and West Germany.

3) The Great Wall of China is not visible from space without aid, contrary to popular belief.

4) The world's oldest tree is believed to be a bristlecone pine named "Methuselah" in California, estimated to be over 4,800 years old.