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 Age of Exploration, during the 15th and 16th centuries, saw European explorers such as Christopher Columbus and Vasco da Gama reach new lands and establish trade routes.

3) Cyclones, also known as hurricanes or typhoons, are powerful tropical storms characterized by low-pressure centers and strong winds.

4) The discovery of the Americas by Christopher Columbus in 1492 opened up new trade routes and had a profound impact on world history.