bu backunuitbu backuunitstand by device備用: reserve; spare; alternate; b ...器件: device; parts of an apparatu ...器件: device; parts of an apparatus or appliance; component 電子器件 electronic device備用: reserve; spare; alternate; backup; standby application; standby分用器: demultiplexer demux下載手機(jī)詞典可隨時隨地查詞查翻譯