But as these stocks rapidly decrease a new study has shown that natural gas, mainly methane, could be found deeper, within the Earth in the mantle.是什么意思_But as these stocks rapidly decrease a new study has shown that natural gas, mainly methane, could be found deeper, within the Earth in the mantle.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句