Question: In Spain, which optical telescope has the minimum focal length?
Paraphrase: Which optical telescope located in Spain has the minimum focal length?
SPARQL (Wikidata): select ?ent where { ?ent wdt:P31 wd:Q35273 . ?ent wdt:P2151 ?obj . ?ent wdt:P17 wd:Q29} ORDER BY ASC(?obj)LIMIT 5 
Answer: Dutch Open Telescope, Isaac Newton Telescope, ESA Optical Ground Station, Swedish Solar Telescope, Galileo National Telescope