What is the {railway electrification system} with the {MAX(frequency)} ?
Of all railway electriciation systems, which uses the highest frequency?
which railway electrification system has the highest frequency?
SELECT ?e WHERE { ?e property:frequency ?h . ?e rdf:type ontology:railway_electrification_system }
select ?ent where {
?ent <http://www.wikidata.org/entity/P31> <http://wikidata.dbpedia.org/resource/Q388201>.
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> ?ent .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P2144>.
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj .}
ORDER BY DESC(?obj)
LIMIT 5
select ?ent where { ?ent wdt:P31 wd:Q388201 . ?ent wdt:P2144 ?obj } ORDER BY DESC(?obj)LIMIT 5 
25 kV AC railway electrification 20 kV AC railway electrification 12.5 kV, 60 Hz AC railway electrification 25 kV, 60 Hz AC railway electrification 20 kV, 60 Hz AC railway electrification