Question: Who produces the trains operated by the MTR?
SPARQL query: SELECT DISTINCT ?uri WHERE { ?x <http://dbpedia.org/ontology/operator> <http://dbpedia.org/resource/MTR> . ?x <http://dbpedia.org/ontology/manufacturer> ?uri  . ?x <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/Train>}
Answer: The manufacturers of the trains operated by the MTR are [Construcciones y Auxiliar de Ferrocarriles, Adtranz, Alstom, Metro Cammell, Hyundai Rotem, Mitsubishi, CSR Sifang Co Ltd., Kinki Sharyo, Kawasaki Heavy Industries Rolling Stock Company, Changchun Railway Vehicles].