1) The construction of the Great Wall of China began in the 7th century BC and was completed over several centuries, spanning thousands of miles.

2) The ozone layer, located in the Earth's stratosphere, protects us from harmful ultraviolet (UV) radiation.

3) The highest-grossing film of all time is "Avengers: Endgame," which has earned over $2.79 billion at the global box office.

4) The world's longest traffic jam occurred in China in 2010 and lasted for 12 days, stretching over 60 miles (97 km).