SELECT DISTINCT ?uri WHERE {?uri <http://dbpedia.org/ontology/leftTributary> <http://dbpedia.org/resource/Zarqa_River> . ?uri <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/River>}
What is the river whose tributary is Zarqa River?
SELECT DISTINCT ?c WHERE { ?c rdf:type ontology:River . ?c property:left_tributary resource:Zarqa_River }
Jordan River
The river whose left tributary is Zarqa River is [Jordan River].
River whose left tributary is the Zarqa River, [Jordan].
[Jordan River] is the river whose left tributary is location.
[Jordan] is the river.