1) The Mona Lisa, painted by Leonardo da Vinci, is one of the most famous and valuable artworks in the world.

2) The Arctic Ocean is the smallest and shallowest ocean, located at the North Pole. It is covered by sea ice for much of the year.

3) The most-watched TV series finale in the United States was "MAS*H," with an estimated 105 million viewers.

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