Question: Through which states do the rivers flow which join in the republican river from the left?
SPARQL query: SELECT DISTINCT ?uri WHERE { <http://dbpedia.org/resource/Republican_River> <http://dbpedia.org/ontology/leftTributary> ?x . ?x <http://dbpedia.org/ontology/state> ?uri  . }
Answer: The states of the river which are the left tributary of Republican River are [Colorado, Nebraska].