How many {first aid measures} are for {mercury poisoning} ?
What is the total number of first aid measures that are available for mercury poisoning?
How many first aid measures are there for mercury poisoning?
SELECT ( COUNT ( ?x ) AS ?e ) { resource:mercury_poisoning property:first_aid_measures ?x }
SELECT (COUNT(?obj) AS ?objs ) {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q408089> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P2239> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj .
} 

SELECT (COUNT(?obj) AS ?value ) { wd:Q408089 wdt:P2239 ?obj }
6