Question: What amusement park located in Houston, Texas opened prior to 1997?
Answer(s):
answer: Hanna–Barbera Land
answer: Wet'n'Wild SplashTown

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:amusement_parks.park.opened ?num .
FILTER (?num < "1997"^^xsd:dateTime) . 
}