1) The word "banana" contains three vowels: A, A, and A.

2) 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.

3) The game of baseball, often referred to as "America's pastime," is played between two teams of nine players and has a rich history dating back to the 18th century.

4) The word "school" contains two vowels: O and O.