基本解释[数学]三重对称三次对称英汉例句双语例句And fivefold, threefold and twofold axes of rotational symmetry.五重，三重和两重螺旋对称轴。threefold symmetry更多例句词组短语短语threefold axis of symmetry 三重对称轴threefold symmetry更多词组专业释义数学三重对称三次对称