Question: Which government canceled the aircraft known as the Avro Arrow?
Sentence (from "Avro Canada CF-105 Arrow"): The CF-105 (Mark 2) held the promise of near-Mach 2 speeds at altitudes of 50000 feet and was intended to serve as the Royal Canadian Air Force's (RCAF) primary interceptor in the 1960s and beyond.
Relevant evidence: No