Columbus first sighted which Venezuelan river in 1498, though it was not explored until 33 years later?

Which two colors blend to make chartreuse? The constellation Columba represents which bird that Noah sent from the ark? Columbia is the capital of which Southern state? Columbia University was founded in 1754 as King's College by royal charter of which English king? What was the name of Columbus's flagship on his first voyage across the Atlantic? Columbus, Ohio, native Buster Douglas was a 1990 champion in which sport, known as "the sweet science"? In which year did Columbus first reach the South American mainland, on his third voyage? Columbus sighted which volcanic Caribbean island in 1493, naming it after a jagged mountain in Spain?