Question: Through which important cities the does the river originating from the Duwamish, flow?
SPARQL query:
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX res: <http://dbpedia.org/resource/>
PREFIX onto: <http://dbpedia.org/ontology/>
SELECT DISTINCT ?uri WHERE { ?x onto:source <http://dbpedia.org/resource/Green_River_(Duwamish_River)> . ?x onto:city ?uri . ?x rdf:type onto:River}