1) 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.

2) The Great Barrier Reef in Australia is the largest living structure on Earth and can be seen from space.

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

4) The Victoria Falls, situated on the Zambezi River between Zambia and Zimbabwe, is one of the largest and most spectacular waterfalls in the world. It is over 1.7 kilometers (1 mile) wide and has a height of 108 meters (354 feet), attracting visitors with its breathtaking beauty and power.