Question: Where does the river end, into which the Rakitnica flows?
SPARQL query: SELECT DISTINCT ?uri WHERE { ?x <http://dbpedia.org/ontology/rightTributary> <http://dbpedia.org/resource/Rakitnica> . ?x <http://dbpedia.org/ontology/mouthCountry> ?uri  . }
Answer: The mouth country of the river whose right tributary is Rakitnica is [Croatia].