Trivia: What is the second-longest river in South America?
Orinoco River
Paraguay River
Paraná River
Rio Negro
The correct answer is Paraná River
So why is this answer correct? : The Amazon River is at least 4,000 miles long, but after the Amazon, the second-longest river in South America is the Paraná, whose 3,032-mile span begins in Brazil and runs south through Paraguay and into Argentina. There, it joins the Uruguay River to form the Río de la Plata estuary, which flows into the Atlantic Ocean.