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

2) The concept of reinsurance, which is insurance for insurance companies, originated in the 17th century.

3) The tongue of a blue whale is so big that about 50 people could stand on it.

4) Sushi is a traditional Japanese dish made of vinegared rice combined with various ingredients, such as raw or cooked seafood, vegetables, and nori (seaweed). It is known for its artful presentation and delicate flavors, and has gained immense popularity worldwide. Sushi can take many forms, including nigiri (hand-pressed rice topped with ingredients) and maki (rolled sushi wrapped in seaweed), and is often enjoyed with soy sauce, wasabi, and pickled ginger.