1) The NBA (National Basketball Association) is widely regarded as one of the most popular and competitive professional basketball leagues in the world.

2) The ozone layer, located in the Earth's stratosphere, protects us from harmful ultraviolet (UV) radiation.

3) The shortest scheduled commercial flight lasts just 1.7 miles and connects two Scottish islands, Westray and Papa Westray.

4) The word "piano" contains three vowels: I, A, and O.