The under-liquid foam extinguishing system is safe,reliable and easy to put out a fire with a low cost, its defect is leakage in the check valve.是什么意思_The under-liquid foam extinguishing system is safe,reliable and easy to put out a fire with a low cost, its defect is leakage in the check valve.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句