The sleeve also rises up the shaft, and when it rises beyond a certain point, it operates a throttle valve lever, and so reduces the flow of steam.是什么意思_The sleeve also rises up the shaft, and when it rises beyond a certain point, it operates a throttle valve lever, and so reduces the flow of steam.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句