Question: Give me the start time for Xi'an has twinned administrative body as Dortmund ?
Paraphrase: What is the start time for Xi'an has paired administrative body as Dortmund ?
SPARQL (Wikidata): SELECT ?value WHERE { wd:Q5826 p:P190 ?s . ?s ps:P190 wd:Q1295 . ?s pq:P580 ?value}