Undulation is one of the fundamental models of the geological effect , the undulation motion and variation inshape of earth crust is an geologic facts.是什么意思_Undulation is one of the fundamental models of the geological effect , the undulation motion and variation inshape of earth crust is an geologic facts.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句