For 10 points, name this river which flows through Asuncion in its namesake country.
Near Pilar, the Bermejo River flows into this river, and another tributary of this river is the Cuiaba, which meets it at Corumba. Other cities on this river include Caceres, Concepcion and Formosa, and it forms the boundary between four provinces and the large Presidente Hayes province in one country. At the largest city on this river, the Pilcomayo branches off to form a border with Argentina. For 10 points, name this river which flows through Asuncion in its namesake country.
Near Pilar, the Bermejo River flows into this river, and another tributary of this river is the Cuiaba, which meets it at Corumba.
{Paraguay} River