What currencies are circulated in the countries where people speak French?
SELECT DISTINCT ?uri WHERE { ?x <http://dbpedia.org/ontology/officialLanguage> <http://dbpedia.org/resource/French_language> . ?x <http://dbpedia.org/ontology/currency> ?uri  . ?x <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/Location>}
French_language