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MedFlight  is a not-for-profit air and ground critical care transportation company based in  Columbus  Ohio that completes critical care transports by helicopter and mobile intensive care units .
 city of headquarters: MedFlight, Columbus
Given options, please tell me the relationships of all the listed entity pairs.Output format is "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} 
 Entity Pairs:  MedFlight, Columbus 
Answer:
 city of headquarters: MedFlight, Columbus