Complex sentence: The 10th Aerospace Defense Group was inactivated on 31 December 1970 by the United States Air Force (USAF) organization when at its last assignment was with Fourteenth Aerospace Force at Vandenberg Air Force Base, California.
Split into simpler sentences: The 10th Aerospace Defense Group was inactivated on 31 December 1970 by the United States Air Force (USAF). Its last assignment was with Fourteenth Aerospace Force at Vandenberg Air Force Base, California.