717
Martin State Airport is linked to downtown Baltimore by two major highways I-95 and U.S. Route 40 and  MARC  commuter rail service between Baltimore's Penn Station and its nearby Martin State Airport  MARC Train  stop .
 MARC, MARC Train
Please list all entity pairs containing a certain relationship in the given options.Output format is "word1, word2; 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:
 MARC, MARC Train