1) Mountains are formed through various geological processes, including tectonic plate movements, volcanic activity, and erosion.

2) The speed of a sneeze can reach up to 100 miles per hour (160 kilometers per hour).

3) The World Wide Web, developed by Tim Berners-Lee in 1989, revolutionized the way information is accessed and shared on the internet.

4) Robert Downey Jr. is an American actor known for his portrayal of Iron Man in the Marvel Cinematic Universe. He has also starred in films such as "Sherlock Holmes," "Chaplin," and "Tropic Thunder," and has received critical acclaim and commercial success for his performances.