Question: The river that powers the dam in Parana Brazil forms the boundary between what countries?
Sentence (from "Bento Munhoz Hydroelectric Plant"): The Governor Bento Munhoz da Rocha Netto Hydroelectric Plant, formerly known as Foz do Areia, is dam and hydroelectric power plant on the Iguazu River near Foz do Areia in Paraná, Brazil.
Relevant evidence: Yes