What is {speed of sound} of {mercury} that is {phase of matter} is {liquid} ?
What is the speed of sound of fluid mercury?
What is the speed of sound of liquid mercury?
SELECT ?j WHERE { ?i property:phase_of_matter resource:liquid . resource:Mercury property:speed_of_sound ?i . ?i property:speed_of_sound ?j }
select distinct ?obj  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q925> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P2075> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj .
?statement <http://www.wikidata.org/entity/P515> <http://wikidata.dbpedia.org/resource/Q11435>
} 

SELECT ?obj WHERE { wd:Q925 p:P2075 ?s . ?s ps:P2075 ?obj . ?s pq:P515 wd:Q11435 }