1) Robert Downey Jr. is an American actor known for his portrayal of Iron Man in the Marvel Cinematic Universe. He has also starred in films such as "Sherlock Holmes," "Chaplin," and "Tropic Thunder," and has received critical acclaim and commercial success for his performances.

2) The name "Bluetooth" comes from the 10th-century Danish king, Harald Bluetooth, who united Denmark and Norway.

3) Native American mythology is incredibly diverse, with numerous tribes and cultures across North and South America having their own unique traditions and stories. It encompasses deities, nature spirits, tricksters, and heroes, reflecting the deep connection between indigenous peoples and the natural world.

4) The Olympic Games, originating in ancient Greece, were revived in 1896 and are now held every four years, bringing together athletes from around the world.