Question: Name a unit used to measure frequency.
SPARQL (Wikidata):  select distinct ?sbj where { ?sbj wdt:P111 wd:Q11652 . ?sbj wdt:P31 wd:Q21162604 } 
Answer: megahertz, beats per minute, actions per minute, kilohertz, gigahertz, cycle per second, terahertz, exahertz, petahertz, femtohertz, picohertz, nanohertz, microhertz, millihertz, centihertz, decihertz, decahertz, hectohertz, beats per minute