1) Bats are the only mammals capable of sustained flight.

2) The process of nuclear fusion powers the sun and other stars, fusing hydrogen atoms together to form helium and releasing vast amounts of energy in the process.

3) The phenomenon known as "black holes" occurs when matter is crushed into an infinitely small space, creating a gravitational pull so strong that nothing can escape.

4) The Epic of Gilgamesh, originating from ancient Mesopotamia, is one of the oldest surviving works of literature and tells the story of the heroic king Gilgamesh and his quest for immortality. It explores themes of friendship, mortality, and the relationship between humans and the divine.