1) The eye of a cyclone is a region of calm, relatively clear skies and light winds at the center of the storm.

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 Eiffel Tower can be 15 cm taller during the summer due to thermal expansion.

4) The concept of campaign finance refers to the funding and financial resources required to support political campaigns, including donations from individuals, organizations, and political action committees (PACs).