in the measurement system international system of units what is the unit of frequency?
Entity Entity Entity Entity
m.03nsh m.02n9swl m.04j3wb3 g.121lm_nv
Hertz Megahertz Kilohertz Gigahertz
class entity
measurement_unit.unit_of_frequency m.0c13h
measurement_unit.unit_of_frequency measurement_unit.measurement_system
Unit of frequency International System of Units
none none
measurement_unit.unit_of_frequency.measurement_system
Measurement system
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_frequency . 
VALUES ?x1 { :m.0c13h } 
?x0 :measurement_unit.unit_of_frequency.measurement_system ?x1 . 
FILTER ( ?x0 != ?x1  )
}
}
(AND measurement_unit.unit_of_frequency (JOIN measurement_unit.unit_of_frequency.measurement_system m.0c13h))