1) 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.

2) Brad Pitt is an American actor and film producer. He has starred in a wide range of films, including "Fight Club," "Inglourious Basterds," and "Once Upon a Time in Hollywood," and has received critical acclaim and numerous awards for his performances.

3) The study of fossils is called paleontology, and it helps us understand the history of life on Earth and the process of evolution.

4) Will Smith is an American actor, rapper, and producer known for his roles in films such as "Men in Black," "Independence Day," and "The Pursuit of Happyness." He has achieved success in both the music and film industries and has received numerous accolades for his work.