Question: Mota Engil built bridges over which rivers?
SPARQL:
SELECT DISTINCT ?uri WHERE { ?x <http://dbpedia.org/property/builder> <http://dbpedia.org/resource/Mota-Engil> . ?x <http://dbpedia.org/ontology/crosses> ?uri  . ?x <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/Bridge>}