1) The musical "The Phantom of the Opera" has been running in London's West End since 1986, making it the longest-running musical in history.

2) The concept of sovereignty refers to the supreme authority and power of a state to govern itself, make decisions, and control its own territory without interference from external forces.

3) The pho, a Vietnamese noodle soup, is a signature dish of Vietnamese cuisine. It typically features a flavorful broth, rice noodles, and various toppings, such as thinly sliced beef or chicken, herbs, bean sprouts, and lime. Pho is often enjoyed for breakfast or as a comforting meal any time of the day. It is known for its complex flavors, aromatic herbs, and the balance between the savory broth and fresh ingredients.

4) The first consumer digital video recorder (DVR), the TiVo, was introduced in 1999 and allowed users to record and store television programs for later viewing.