Question: Of the tourist attractions that are in Houston, Texas, which one's a zoo that opened on, or after September of 1922?
Answer(s):
answer: Downtown Aquarium, Houston

SPARQL query:
PREFIX ns: <http://rdf.freebase.com/ns/>
SELECT DISTINCT ?x
WHERE {
FILTER (?x != ns:m.03l2n)
FILTER (!isLiteral(?x) OR lang(?x) = '' OR langMatches(lang(?x), 'en'))
ns:m.03l2n ns:travel.travel_destination.tourist_attractions ?x .
?x ns:zoos.zoo.opened ?num .
FILTER (?num > "1922-09"^^xsd:dateTime) . 
}