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

2) Serena Williams, an American tennis player, has won a total of 23 Grand Slam singles titles, making her one of the most successful players in the history of the sport.

3) The concept of self-driving cars, or autonomous vehicles, is being actively developed by companies such as Tesla, Google (Waymo), and Uber.

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.