1) The Tour de France, first held in 1903, is one of the most prestigious and grueling cycling races, covering over 3,500 kilometers (2,200 miles) in three weeks.

2) The concept of political stability refers to the ability of a government or political system to maintain continuity, order, and effective governance over a prolonged period, promoting social cohesion and economic development.

3) 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.

4) In Norse mythology, the Valkyries are divine maidens who serve Odin, the chief god. They are responsible for selecting warriors worthy of entering Valhalla and escorting them to the afterlife. They are often depicted as powerful and beautiful figures, riding winged horses and wielding spears.