air horn
空气喇叭
气流振响报警号
角形气隙
气喇叭
气压警报器
气笛
气号
汽笛
空气报警器
unidentified air intelligence
Uninhabited air vehicle
Uninhabited Combat Air Vehicle
Uninhabited Combat Air Vehicle UCAV
Uninhabited Combat Air Vehicle UCAV team
Uninhabited Combat Air Vehicle(UCAV) team
unit air filtering system
Unitary Air Conditioner
unitary air -conditioner
unknown air intelligence