Did {Air_pollution} {has cause} {methane} and {volcanic eruption} ?
Does methane and volcanic eruption causes air pollution ?
Is air pollution caused by methane and volcanic eruption?
ASK WHERE { resource:air_pollution property:has_cause resource:volcanic_eruption . resource:air_pollution property:has_cause resource:methane }
 ASK { ?statement1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q131123> . ?statement1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P828> . ?statement1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <http://wikidata.dbpedia.org/resource/Q37129>. ?statement2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q131123> . ?statement2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P828> . ?statement2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <http://wikidata.dbpedia.org/resource/Q7692360>. } 
ASK WHERE { wd:Q131123 wdt:P828 wd:Q37129 . wd:Q131123 wdt:P828 wd:Q7692360 }