List the profession of senate whose one of the profession is United States Coast Guard ?
SELECT DISTINCT ?uri WHERE { ?x <http://dbpedia.org/ontology/profession> <http://dbpedia.org/resource/United_States_Coast_Guard> . ?x <http://dbpedia.org/ontology/profession> ?uri  . ?x <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/Politician>}
United_States_Coast_Guard