air gap pd的相關資料：
臨近單詞
airglow
air
air-dried volumetric specific gravity
Air Force Educational Requirement Board
AirForce Intelligence Reserve Programme
Air Traffic Control Coordination Center
Air Target Intelligence Liaison Program
Air Defense Battle Management Simulator
Air quality automation monitoring system
Aircrew Intelligence Orientation Program
Air Defense Artillery Operations Officer
air entrainment to alleviate cavitations
