Question: In which country does the Nile start?
SPARQL:
PREFIX onto: <http://dbpedia.org/ontology/>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX res: <http://dbpedia.org/resource/>
SELECT ?uri ?string
WHERE 
{       
        res:Nile onto:sourceCountry ?uri .
        OPTIONAL {?uri rdfs:label ?string. FILTER (lang(?string) = 'en') }
}