Question: What discovery did the academic advisor of Vincenzo Viviani make?
Answer(s):
answer: Io
answer: Callisto
answer: Europa
answer: Ganymede

SPARQL query:
PREFIX ns: <http://rdf.freebase.com/ns/>
SELECT DISTINCT ?x
WHERE {
FILTER (?x != ?c)
FILTER (!isLiteral(?x) OR lang(?x) = '' OR langMatches(lang(?x), 'en'))
?c ns:education.academic.advisees ns:m.04hnf4 . 
?c ns:astronomy.astronomer.astronomical_objects_discovered ?x .
}