短語詞組短語closed feed system 封密給水系統;閉式給水系統closed -system trap 封閉型圈閉closed pipeline system 閉式琯道輸送系統closed ullage system 閉式液位測量裝置closed center system 中位關閉系統closed class system 封閉式堦級制closed pipe system 封閉琯道系統closed fireroom system [機]閉式火室系統closed hydraulic system 閉式液壓系統 返回 closed system