machine_question: what is the political system in the location contains and airport that server Duisburg
question: What is the political system in the place that contains an airport that serves Duisburg?
sparql: PREFIX ns: <http://rdf.freebase.com/ns/>
  SELECT DISTINCT ?x
  WHERE {
  FILTER (?x != ?c)
  FILTER (!isLiteral(?x) OR lang(?x) = '' OR langMatches(lang(?x), 'en'))
  ?c ns:location.location.contains ?k .
  ?k ns:aviation.airport.serves ns:m.0ps1q . 
  ?c ns:location.country.form_of_government ?x .
  }
  
webqsp_question: what is the political system in germany