1) The word "oxygen" contains two vowels: O and E.

2) The oldest known musical instrument is a flute made from a bird bone, estimated to be around 43,000 years old.

3) The role of lobbyists in politics involves representing the interests of specific groups or industries and advocating for favorable policies or influencing decision-making processes within government institutions.

4) 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.