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 term "bull market" refers to a period of rising stock prices, while a "bear market" refers to a period of falling stock prices.

3) The word "yesterday" contains three vowels: E, A, and A.

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