The machine is used to roll the sheet ends of rectangular airducts to form a flange for connecting the other duct flange instead of L-steel flange.是什么意思_The machine is used to roll the sheet ends of rectangular airducts to form a flange for connecting the other duct flange instead of L-steel flange.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句