Question: Which limestone powder has the highest emissivity?
Paraphrase: Which limestone powder has the most potential to radiate energy?
SPARQL (Wikidata): select ?ent where { ?ent wdt:P31 wd:Q2908004 . ?ent wdt:P1295 ?obj . ?ent wdt:P186 wd:Q23757 } ORDER BY DESC(?obj)LIMIT 5 
Answer: cement