Question: Which  siler medalist of the Tennis at the 2012 Summer Olympics  Men's singles was also the  flagbearer of the Switzerland at the 2008 Summer Olympics
SPARQL query:
PREFIX prop: <http://dbpedia.org/property/>
PREFIX onto: <http://dbpedia.org/ontology/>
 SELECT DISTINCT ?uri WHERE { <http://dbpedia.org/resource/Tennis_at_the_2012_Summer_Olympics_–_Men's_singles> onto:silverMedalist ?uri. <http://dbpedia.org/resource/Switzerland_at_the_2008_Summer_Olympics> prop:flagbearer ?uri}