sentences:  The river was known as "Zaire" during the 16th and 17th centuries; "Congo" seems to have replaced "Zaire" gradually in English usage during the 18th century, and "Congo" is the preferred English name in 19th-century literature, although references to "Zaire" as the name used by the natives (i.e.derived from Portuguese usage) remained common.In 1992, the Sovereign National Conference voted to change the name of the country to the "Democratic Republic of the Congo", but the change was not made.