Which Class IB flammable liquid ester has the lowest vapor pressure?
select ?ent where { ?ent wdt:P31 wd:Q21009055 . ?ent wdt:P2119 ?obj . ?ent wdt:P31 wd:Q101487} ORDER BY ASC(?obj)LIMIT 5 
class ib flammable liquid: Q21009055 ester: Q101487