1) The hibiscus flower is commonly associated with tropical regions and is the national flower of several countries, including Malaysia, South Korea, and Haiti.

2) The book series "The Chronicles of Narnia" by C.S. Lewis has sold over 100 million copies worldwide.

3) The sunflower is not a single flower but a cluster of small flowers arranged in a spiral pattern.

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