Context: Ecuador, officially the Republic of Ecuador (which literally translates as "Republic of the Equator"), is a representative democratic republic in northwestern South America, bordered by Colombia on the north, Peru on the east and south, and the Pacific Ocean to the west. Ecuador also includes the Galápagos Islands in the Pacific, about west of the mainland., The Drake Passage or Mar de HocesSea of Hocesis the body of water between South America's Cape Horn and the South Shetland Islands of Antarctica. It connects the southwestern part of the Atlantic Ocean (Scotia Sea) with the southeastern part of the Pacific Ocean and extends into the Southern Ocean., In geography, latitude is a geographic coordinate that specifies the northsouth position of a point on the Earth's surface. Latitude is an angle (defined below) which ranges from 0° at the Equator to 90° (North or South) at the poles. Lines of constant latitude, or parallels, run eastwest as circles parallel to the equator. Latitude is used together with longitude to specify the precise location of features on the surface of the Earth.
Approximations employed.
Two levels of abstraction are employed in the definition of these coordinates. In the first step the physical surface is modelled by the geoid, a surface which approximates the mean sea level over the oceans and its continuation under the land masses. The second step is to approximate the geoid by a mathematically simpler reference surface. The simplest choice for the reference surface is a sphere, but the geoid is more accurately modelled by an ellipsoid. The definitions of latitude and longitude on such reference surfaces are detailed in the following sections. Lines of constant latitude and longitude together constitute a graticule on the reference surface. The latitude of a point on the "actual" surface is that of the corresponding point on the reference surface, the correspondence being along the normal to the reference surface which passes through the point on the physical surface. Latitude and longitude together with some specification of height constitute a geographic coordinate system as defined in the specification of the ISO 19111 standard., Oceania (or ), also known as Oceanica, is a region centred on the islands of the tropical Pacific Ocean. Opinions of what constitutes Oceania range from its three subregions of Melanesia, Micronesia, and Polynesia to, more broadly, the entire insular region between Southeast Asia and the Americas, including Australasia and the Malay Archipelago., Chile, officially the Republic of Chile, is a South American country occupying a long, narrow strip of land between the Andes to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far south. Chilean territory includes the Pacific islands of Juan Fernández, Salas y Gómez, Desventuradas, and Easter Island in Oceania. Chile also claims about of Antarctica, although all claims are suspended under the Antarctic Treaty., The Melado is a river of Linares province , Maule Region , of Chile . It rises in the `` Cordillera de los Andes '' with the name of river Guaiquivilo where it is formed by two tributaries , the river Cajón Troncoso , born near the Argentine border and the river Palaleo , from the outflow of Dial lake , located some 70 km upstream from the joining of the two rivers . The Guaiquivilo flows northwardly along a typical interandean longitudinal valley . On its left bank the Guaiquivilo is flanked by the Melado sierra , which has peaks that often surpass 2.500 mt and which constitute a natural barrier between the Guaiquivilo basin and those of the rivers Longaví , Achibueno and Ancoa , all tributary of the river Loncomilla , which , in its turn , is the main tributary of river Maule . On its right bank , the Guaiquivilo is joined by the river San Pedro or La Puente which is born from a glacier related to the San Pedro ( or Las Yeguas ) volcano . From this point onwards , the river takes the name of Melado . The river Melado is dammed to generate hydroelectric power in the Pehuenche Hydroelectric Plant . The Melado joins the river Maule when the latter has already flowed for 75 km. The Canal Melado transports water from the Melado river through the Guaiquivilo basin and a tunnel of 4,2 km to the Ancoa River ., Argentina, officially the Argentine Republic, is a federal republic in the southern half of South America. Sharing the bulk of the Southern Cone with its neighbor Chile to the west, the country is also bordered by Bolivia and Paraguay to the north, Brazil to the northeast, Uruguay and the South Atlantic Ocean to the east, and the Drake Passage to the south. With a mainland area of , Argentina is the eighth-largest country in the world, the second largest in Latin America, and the largest Spanish-speaking one. The country is subdivided into twenty-three provinces (singular "provincia") and one autonomous city ("ciudad autónoma"), Buenos Aires, which is the federal capital of the nation as decided by Congress.
The provinces and the capital have their own constitutions, but exist under a federal system., Venezuela, officially the Bolivarian Republic of Venezuela, is a federal republic located on the northern coast of South America. It is bordered by Colombia on the west, Brazil on the south, Guyana on the east, and the islands of Trinidad and Tobago to the north-east. Venezuela's territory covers around with an estimated population . Venezuela is considered a state with extremely high biodiversity (currently ranks 7th in the world's list of nations with the most number of species), with habitats ranging from the Andes Mountains in the west to the Amazon Basin rain-forest in the south, via extensive "llanos" plains and Caribbean coast in the center and the Orinoco River Delta in the east., Easter Island is a Chilean island in the southeastern Pacific Ocean, at the southeasternmost point of the Polynesian Triangle. Easter Island is famous for its 887 extant monumental statues, called "moai", created by the early Rapa Nui people. In 1995, UNESCO named Easter Island a World Heritage Site, with much of the island protected within Rapa Nui National Park., The Maule river or Río Maule (Mapudungun: "rainy") is one of the most important rivers of Chile. It is inextricably linked to the country's pre-Hispanic (Inca) times, the country's conquest, colonial period, wars of Independence, modern history, agriculture (wine, traditional crops), culture (literature, poetry, folklore), religion, economy and politics. The Maule River marked the southern limits of the Inca Empire. Many famous men and women in Chile's history have been born in the Region named after the river. The river has also lent its name to one of the viticultural regions of the country (also known as appellations), the Valley of Maule, a subregion of the Central Valley., The VII Maule Region is one of Chile's 15 first order administrative divisions. Its capital is Talca. The region derives its name from the Maule River which, running westward from the Andes, bisects the region and spans a basin of about 20,600 km. The Maule river is of considerable historic interest because, among other reasons, it marked the southern limits of the Inca Empire., The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south and is bounded by Asia and Australia in the west and the Americas in the east., The Andes or Andean Mountains are the longest continental mountain range in the world. They are a continuous range of highlands along the western edge of South America. This range is about long, about wide (widest between 18° south and 20° south latitude), and of an average height of about . The Andes extend from north to south through seven South American countries: Venezuela, Colombia, Ecuador, Peru, Bolivia, Argentina and Chile., Peru , officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the west by the Pacific Ocean. Peru is an extremely biodiverse country with habitats ranging from the arid plains of the Pacific coastal region in the west to the peaks of the Andes mountains vertically extending from the north to the southeast of the country to the tropical Amazon Basin rainforest in the east with the Amazon river., Antarctica (US English , UK English or ) is Earth's southernmost continent. It contains the geographic South Pole and is situated in the Antarctic region of the Southern Hemisphere, almost entirely south of the Antarctic Circle, and is surrounded by the Southern Ocean. At , it is the fifth-largest continent. For comparison, Antarctica is nearly twice the size of Australia. About 98% of Antarctica is covered by ice that averages in thickness, which extends to all but the northernmost reaches of the Antarctic Peninsula., Tin is a chemical element with the symbol Sn (for ) and atomic number 50, is a post-transition metal in group 14 of the periodic table. It is obtained chiefly from the mineral cassiterite, which contains tin dioxide, SnO. Tin shows a chemical similarity to both of its neighbors in group 14, germanium and lead, and has two main oxidation states, +2 and the slightly more stable +4. Tin is the 49th most abundant element and has, with 10 stable isotopes, the largest number of stable isotopes in the periodic table, thanks to its magic number of protons. It has two main allotropes: at room temperature, the stable allotrope is -tin, a silvery-white, malleable metal, but at low temperatures it transforms into the less dense grey -tin, which has the diamond cubic structure. Metallic tin is not easily oxidized in air., Subject: melado river, Relation: mouth_of_the_watercourse, Options: (A) amazon (B) arctic ocean (C) atlantic ocean (D) main (E) maule river (F) pacific ocean (G) sea (H) southern ocean
Output: maule river