1) The Boston Celtics and the Los Angeles Lakers are the most successful teams in NBA history, with a combined total of 33 championships.

2) The Berlin Conference in 1884-1885 divided Africa among European powers and set the stage for the colonization of the continent.

3) The first graphical web browser, Mosaic, was released in 1993 and played a key role in popularizing the World Wide Web.

4) The Southern Ocean surrounds Antarctica and is the coldest and least-visited ocean.