Question: For how many different presidents have people in the Continental Army served?
SPARQL query: SELECT DISTINCT COUNT(?uri) WHERE { ?x <http://dbpedia.org/property/branch> <http://dbpedia.org/resource/Continental_Army> . ?x <http://dbpedia.org/property/president> ?uri  . }
Answer: There are [17] Presidents to which the people in the Continental Army have served.