What is the {flammable gas} with the {MAX(short-term exposure limit)} whose {has effect} is {formaldehyde exposure}  ?
What gas causes a formaldehyde exposure?
Name the gas that can cause formaldehyde exposure ?
SELECT ?b WHERE { ?b property:short-term_exposure_limit ?n . ?b property:has_effect resource:formaldehyde_exposure . ?b rdf:type ontology:Q21073026 }
select ?ent where {
?ent <http://www.wikidata.org/entity/P31> <http://wikidata.dbpedia.org/resource/Q21073026>.

?statement1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> ?ent .
?statement1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P2407>.
?statement1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj1.

?statement2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> ?ent .
?statement2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P1542> .
?statement2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <http://wikidata.dbpedia.org/resource/Q21174328> .

}
ORDER BY DESC(?obj1)
LIMIT 5
select ?ent where { ?ent wdt:P31 wd:Q21073026 . ?ent wdt:P2407 ?obj . ?ent wdt:P1542 wd:Q21174328 } ORDER BY DESC(?obj)LIMIT 5 