1) A single bolt of lightning can heat the surrounding air to temperatures five times hotter than the surface of the sun.

2) The concept of virtual reality (VR) involves creating a simulated environment that can be explored and interacted with using specialized headsets and input devices.

3) The word "book" contains two vowels: O and O.

4) The highest-grossing film of all time is "Avengers: Endgame," which has earned over $2.79 billion at the global box office.