In how many states can one find Burr Tuss kind of bridges?
SELECT DISTINCT COUNT(?uri) WHERE { ?x <http://dbpedia.org/property/style> <http://dbpedia.org/resource/Burr_Truss> . ?x <http://dbpedia.org/ontology/state> ?uri  . ?uri <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/Region>}
Burr_Truss