At the same time, the author also provides the computational for mula (5) and (6) of the optimun ralation speed which he has deri...是什么意思_At the same time, the author also provides the computational for mula (5) and (6) of the optimun ralation speed which he has deri...在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句