1) The highest mountain in Africa is Mount Kilimanjaro, standing at 19,341 feet (5,895 meters) tall.

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

3) The Federal Reserve System, often referred to as the Fed, is the central banking system of the United States.

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