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 world's tallest waterfall is Angel Falls in Venezuela, with a height of about 3,212 feet (979 meters).

3) The first commercially successful video game was "Pong," released in 1972 by Atari.

4) The first successful human heart transplant was performed by Dr. Christiaan Barnard in 1967.