1) The ancient city of Pompeii was preserved under layers of volcanic ash after the eruption of Mount Vesuvius in 79 AD, providing valuable insights into Roman life.

2) Tom Hanks is an American actor and filmmaker known for his versatile performances in films such as "Forrest Gump," "Saving Private Ryan," and "Cast Away." He has received numerous awards, including Academy Awards, Golden Globes, and BAFTAs.

3) The Northern Lights, also known as the Aurora Borealis, are natural light displays that occur in the polar regions due to interactions between the Earth's magnetic field and solar particles.

4) The American Civil Rights Movement, led by figures like Martin Luther King Jr., fought for equal rights and helped bring about significant social and legislative changes.