短语词组短语air -duct 通气管道;通风道;导气管;气槽fine air separating duct 后风道air cleaner duct 空气滤清器连接管air cleaner duct clamp 空气滤清器连接管卡子return air ground duct 回风地沟air heater duct 暖风器通道air conditioning duct 空气调节系统管道air conditioner duct 空调风道 返回 air duct