Question: List some people who were opponents of someone who was died by hanging? 
SPARQL:
SELECT DISTINCT ?uri WHERE { ?x <http://dbpedia.org/property/deathCause> <http://dbpedia.org/resource/Hanging> . ?x <http://dbpedia.org/ontology/opponent> ?uri  . ?x <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/Person>}