Question: How many causes of death have been associated with American citizens?
SPARQL query: SELECT DISTINCT COUNT(?uri) WHERE { ?x <http://dbpedia.org/property/citizenship> <http://dbpedia.org/resource/United_States> . ?x <http://dbpedia.org/ontology/deathCause> ?uri  . }
Answer: There are [25] death causes of citizens of the United States.