The carbon number range or the peak carbon number of normal alkanes in crude oils shift backuard and the light/ heavy hydrocarbons ratio show decreasing trendtion.是什么意思_The carbon number range or the peak carbon number of normal alkanes in crude oils shift backuard and the light/ heavy hydrocarbons ratio show decreasing trendtion.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句