In which country is there a dam on the Awash river?
SELECT DISTINCT ?uri WHERE { ?x <http://dbpedia.org/ontology/river> <http://dbpedia.org/resource/Awash_River> . ?x <http://dbpedia.org/property/country> ?uri  . ?x <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/Dam>}
Awash_River