VARIATION OF SOIL ORGANIC CARBON ISOTOPE AND C_3/C_4 VEGETATION TYPE TRANSITION IN THE WESTERN LOESS PLATEAU DURING THE LAST GLACIAL AND HOLOCENE PERIODS是什么意思_VARIATION OF SOIL ORGANIC CARBON ISOTOPE AND C_3/C_4 VEGETATION TYPE TRANSITION IN THE WESTERN LOESS PLATEAU DURING THE LAST GLACIAL AND HOLOCENE PERIODS在线翻译_英语_读音_用法_例句