Which is the longest African river that empties into the Indian Ocean?

What is the largest coral reef system on Earth, stretching along the northeast coast of Australia? Morocco's Mount Toubkal, at about 13,700 feet, is the highest peak of which mountain chain? At about 1,700 square miles, which Utah lake is one of the largest in the world with no outlet? Orbiting at about 17,500 mph, which winged NASA spacecraft flew 135 missions between 1981 and 2011? At about 25,000 feet down, the Cayman Trench is the deepest part of which sea? Which Nepalese peak, at about 29,000 feet, is the highest mountain on Earth above sea level? At about 43,000 square miles, which is the largest independent island nation in the Western Hemisphere? Red Lake, at about 440 square miles, is the largest natural lake entirely within which "Land of 10,000 Lakes" state?