Grain gradation, from coarser below to finer above in repeated, truncated sequences within the Ellerslie Sandstone is also evident.是什么意思_Grain gradation, from coarser below to finer above in repeated, truncated sequences within the Ellerslie Sandstone is also evident.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句