1) The word "piano" contains three vowels: I, A, and O.

2) The concept of augmented reality (AR) involves overlaying digital information and virtual objects onto the real world, enhancing the user's perception and interaction with the environment.

3) The musical "The Phantom of the Opera" has been running in London's West End since 1986, making it the longest-running musical in history.

4) Marilyn Monroe, born Norma Jeane Mortenson, was an iconic American actress, model, and singer, known for her beauty, charisma, and tragic personal life.