1) The Appalachian Mountains, running along the eastern coast of the United States, are one of the oldest mountain ranges in the world.

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

3) The Great Wall of China is not visible from space without aid, contrary to popular belief.

4) The first successful mass-produced personal computer, the IBM PC, was introduced in 1981 and played a significant role in popularizing the use of computers in homes and offices.