1) The word "mountain" contains three vowels: O, U, and A.

2) The first successful portable MP3 player, the Diamond Rio PMP300, was released in 1998 and could hold up to 60 minutes of music.

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

4) Mount Kilimanjaro in Tanzania is the highest mountain in Africa and attracts climbers from around the world.