The valve closed, the torch into the water, then pass into the oxygen and acetylene, there are no air bubbles in water, it proved a good air tightness.是什么意思_The valve closed, the torch into the water, then pass into the oxygen and acetylene, there are no air bubbles in water, it proved a good air tightness.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句