Question: Which man took a government post beginning 1921-03-04 as an Arizona state senator?
Answer(s):
answer: Ralph H. Cameron

SPARQL query:
PREFIX ns: <http://rdf.freebase.com/ns/>
SELECT DISTINCT ?x
WHERE {
FILTER (?x != ns:m.0vmt)
FILTER (!isLiteral(?x) OR lang(?x) = '' OR langMatches(lang(?x), 'en'))
ns:m.0vmt ns:government.political_district.representatives ?y .
?y ns:government.government_position_held.office_holder ?x .
?y ns:government.government_position_held.office_position_or_title ns:m.02_7l8y .
?x ns:government.politician.government_positions_held ?c .
?c ns:government.government_position_held.from "1921-03-04"^^xsd:dateTime . 
}