Question: How many units follow the US Navy Department's command structure?
SPARQL:
SELECT DISTINCT COUNT(?uri) WHERE {?uri <http://dbpedia.org/ontology/commandStructure> <http://dbpedia.org/resource/United_States_Department_of_the_Navy>  . ?uri <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/MilitaryUnit>}