The operational principle of some metering units, such as leadscrew nut mechanism, pendulum bar type metering unit, metering pump, are introduced.是什么意思_The operational principle of some metering units, such as leadscrew nut mechanism, pendulum bar type metering unit, metering pump, are introduced.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句