Question: Where is the residence of the prime minister of Spain?
SPARQL query:
PREFIX prop: <http://dbpedia.org/property/>
PREFIX res: <http://dbpedia.org/resource/>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
SELECT DISTINCT ?uri ?string WHERE 
{
	res:Prime_Minister_of_Spain prop:residence ?uri .
	OPTIONAL { ?uri rdfs:label ?string. FILTER (lang(?string) = 'en') }
}