1) The first modern Olympic marathon race was held at the 1896 Olympics in Athens and has since become one of the most iconic and challenging events in athletics.

2) The development of voice recognition technology has led to the widespread use of virtual assistants such as Siri, Alexa, and Google Assistant.

3) The tongue of a blue whale is so big that about 50 people could stand on it.

4) J.K. Rowling's "Harry Potter" series of books has sold over 500 million copies worldwide and has been translated into 80 languages.