What is {diameter} of {Arecibo Observatory} that is {applies to part} is {Illuminated aperture} ?
How big is the opening of the Arecibo Observatory?
What is the diameter of the Arecibo Observatory which applies to Illuminated aperture?
SELECT ?r WHERE { resource:Arecibo_Radio_Telescope property:diameter ?j . ?j property:applies_to_part resource:illuminated_aperture . ?j property:diameter ?r }
select distinct ?obj  where {
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?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P2386> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> ?obj .
?statement <http://www.wikidata.org/entity/P518> <http://wikidata.dbpedia.org/resource/Q40782571>
} 

SELECT ?obj WHERE { wd:Q44547 p:P2386 ?s . ?s ps:P2386 ?obj . ?s pq:P518 wd:Q40782571 }