1) The world's first credit card was introduced in 1950 by Diners Club.

2) The Nile River, spanning approximately 6,650 kilometers (4,130 miles), is the longest river in the world. It flows through eleven countries in northeastern Africa, supporting various civilizations throughout history and serving as a vital source of water and transportation.

3) The world's first car radio was invented in 1929.

4) The novel "To Kill a Mockingbird" by Harper Lee has been translated into more than 40 languages and has sold over 40 million copies worldwide.