1) The word "mountain" contains three vowels: O, U, and A.

2) The concept of quantum computing explores the use of quantum mechanics principles to perform complex computations, potentially revolutionizing fields such as cryptography and optimization.

3) The Dead Sea, located between Jordan and Israel, is the lowest point on Earth's surface. Its saltwater is so dense that people can easily float on its surface.

4) The sitcom "Friends" is known for its iconic Central Perk coffee shop, where the main characters often gather.