The tube-insert can be filled with liquid or other substance to make its average density equal to the flowing fluid in heat transfer tubes, thus it can float and spin concentrically with axis.是什么意思_The tube-insert can be filled with liquid or other substance to make its average density equal to the flowing fluid in heat transfer tubes, thus it can float and spin concentrically with axis.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句