In this paper, we make use of the properties of the umbilic to research circle Section question of quadric in 3-dimensional euclidean space.We give the equations of these circle sections.是什么意思_In this paper, we make use of the properties of the umbilic to research circle Section question of quadric in 3-dimensional euclidean space.We give the equations of these circle sections.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句