1) The word "book" contains two vowels: O and O.

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

3) Cristiano Ronaldo is a Portuguese professional soccer player widely regarded as one of the greatest footballers of all time. He has won numerous awards, including multiple FIFA Ballon d'Or titles, and has played for top clubs such as Manchester United, Real Madrid, and Juventus.

4) The Edelweiss flower, found in the European Alps, is known for its beauty and is often associated with mountaineering and alpine culture.