Question: What is an SI Base unit that starts with the letter s.
Paraphrase: What is a unit of SI Base starting with the letter s.
SPARQL (Wikidata): SELECT DISTINCT ?sbj ?sbj_label WHERE { ?sbj wdt:P31 wd:Q223662 . ?sbj rdfs:label ?sbj_label . FILTER(STRSTARTS(lcase(?sbj_label), 's')) . FILTER (lang(?sbj_label) = 'en') } LIMIT 25 
Answer: second, second