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

2) The first successful portable MP3 player, the Diamond Rio PMP300, was released in 1998 and could hold up to 60 minutes of music.

3) International relations encompass the study of relationships between nations, including diplomacy, treaties, and foreign policy. It examines the interactions and dynamics among different countries in the global arena.

4) Automated Teller Machines (ATMs) allow individuals to perform banking transactions, such as withdrawing cash, outside of traditional bank branches.