what is the measure for a unit of density that shares a measurement system with kilometres per second as a measure of speed?
Entity
m.0d1kg
Kilogram per cubic metre
class class entity
measurement_unit.unit_of_density measurement_unit.measurement_system g.12hhgrkjc
measurement_unit.unit_of_density measurement_unit.measurement_system measurement_unit.speed_unit
Unit of Density Measurement System Kilometres per second
none none none
measurement_unit.unit_of_density.measurement_system measurement_unit.measurement_system.speed_units
Measurement system Speed Units
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> PREFIX : <http://rdf.freebase.com/ns/> 
SELECT (?x0 AS ?value) WHERE {
SELECT DISTINCT ?x0  WHERE { 
?x0 :type.object.type :measurement_unit.unit_of_density . 
?x1 :type.object.type :measurement_unit.measurement_system . 
VALUES ?x2 { :g.12hhgrkjc } 
?x0 :measurement_unit.unit_of_density.measurement_system ?x1 . 
?x1 :measurement_unit.measurement_system.speed_units ?x2 . 
FILTER ( ?x0 != ?x1 && ?x0 != ?x2 && ?x1 != ?x2  )
}
}
(AND measurement_unit.unit_of_density (JOIN measurement_unit.unit_of_density.measurement_system (JOIN measurement_unit.measurement_system.speed_units g.12hhgrkjc)))