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Among others  I-GO  has worked closely with the Chicago Transit Authority City of Chicago and  Chicago  Park District .
 city of headquarters: I-GO, Chicago
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:  I-GO, Chicago 
Answer:
 city of headquarters: I-GO, Chicago