Question: No. 11 Squadron is based at an airbase 25 km north of the center of what city?
Sentence (from "Białystok County"): The county contains nine towns: Łapy, 25 km south-west of Białystok, Czarna Białostocka, 22 km north of Białystok, Wasilków, 11 km north of Białystok, Choroszcz, 13 km west of Białystok, Supraśl, 16 km north-east of Białystok, Michałowo, 13 km east of Białystok, Zabłudów, 16 km south-east of Białystok, Tykocin, 29 km west of Białystok, and Suraż, 23 km south-west of Białystok.
Relevant evidence: No