Question: Name the river passing through Reading Berkshire and has mouth place at Essex ?
SPARQL:
SELECT DISTINCT ?uri WHERE {?uri <http://dbpedia.org/ontology/city> <http://dbpedia.org/resource/Reading,_Berkshire> . ?uri <http://dbpedia.org/ontology/mouthPlace> <http://dbpedia.org/resource/Essex>  . ?uri <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/River>}