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Astra IVA is a family of metro train used by  Bucharest Metro  and built in Arad  Romania  between 1976 and 1992 .
 country of headquarters: Bucharest Metro, Romania
Given a phrase that describes the relationship between two words, extract the words and the lexical relationship between them. The output format should be "relation1: word1, word2; relation2: word3, word4". 
Option: cities of residence, top members employees, members, alternate names, origin, state or provinces of residence, title of person, spouse, city of headquarters, NA, founded by, state or province of headquarters, employee of, countries of residence, country of birth, founded, subsidiaries, country of headquarters 
Text: {0} 
Answer:
 country of headquarters: Bucharest Metro, Romania