Where is the main ground of soccer seasons whose chairman is Ronaldo?
SELECT DISTINCT ?uri WHERE { ?x <http://dbpedia.org/ontology/chairman> <http://dbpedia.org/resource/Ronaldo> . ?x <http://dbpedia.org/ontology/ground> ?uri  . ?x <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://dbpedia.org/ontology/SoccerClubSeason>}
Ronaldo