Question: Name a military unit whose command structure is United States Department of the Navy and garrison is Arlington County, Virginia?
SPARQL:
SELECT DISTINCT ?uri WHERE {?uri <http://dbpedia.org/ontology/commandStructure> <http://dbpedia.org/resource/United_States_Department_of_the_Navy> . ?uri <http://dbpedia.org/ontology/garrison> <http://dbpedia.org/resource/Arlington_County,_Virginia>  . ?uri <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/MilitaryUnit>}