At the beginning stage of pumping, the piston compresses the concrete mixture, the pressure in concrete cylinder increases rapidly and the air in concrete mixture is compacted and excluded.是什么意思_At the beginning stage of pumping, the piston compresses the concrete mixture, the pressure in concrete cylinder increases rapidly and the air in concrete mixture is compacted and excluded.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句