1) The world's most expensive car is the Bugatti La Voiture Noire, which sold for over $18 million.

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 Great Wall of China is a UNESCO World Heritage site and one of the most iconic man-made structures in the world. It stretches over 21,196 kilometers (13,171 miles) and was constructed to protect the Chinese empire from invasions during ancient times.

4) A single bolt of lightning can heat the surrounding air to temperatures five times hotter than the surface of the sun.