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

2) The Danube River, flowing through ten countries in Central and Eastern Europe, is the second-longest river in Europe. It has played a significant role in the cultural and economic development of the regions it traverses and is a popular waterway for river cruises.

3) The world's first paper money was created in China over 1,000 years ago.

4) The largest known dinosaur, Argentinosaurus, weighed around 70-100 tons and measured up to 100 feet in length.