It is thought to act like a valve, sealing the pit when the pressure on the two sides is unequal, e.g. when an adjacent tracheid is damaged.是什么意思_It is thought to act like a valve, sealing the pit when the pressure on the two sides is unequal, e.g. when an adjacent tracheid is damaged.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句