1) The highest-grossing concert tour of all time is U2's "360° Tour," which earned over $735 million in ticket sales.

2) The Amazon rainforest produces more than 20% of the world's oxygen.

3) The oldest known musical instrument is a flute made from a bird bone, estimated to be around 43,000 years old.

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