短語詞組短語outside propagation characteristic 外傳播特性wave propagation characteristic 波傳輸特性dual propagation characteristic 雙傳播特性fracture propagation characteristic 裂口擴(kuò)展特性cross propagation characteristic 橫曏傳播特性ultrasonic propagation characteristic 超聲波傳播特性atmospheric propagation characteristic 大氣傳輸特性radio propagation characteristic 無線傳播特性Radio wave propagation characteristic 電波傳播特性 返回 propagation characteristic