Question: What is the colorless Class II combustible liquid with the lowest median lethal concentration?
Paraphrase: What clear Class 2 combustible liquid has the least lethal concentration?
SPARQL (Wikidata): select ?ent where { ?ent wdt:P31 wd:Q21009057 . ?ent wdt:P2712 ?obj . ?ent wdt:P462 wd:Q1396399. } ORDER BY ASC(?obj)LIMIT 5 
Answer: allyl glycidyl ether, allyl glycidyl ether