threefold axis of symmetry的意思|示意
美 / /
英 / /
三重对称轴，三次对称轴
threefold axis of symmetry的网络常见释义
三重对称轴 ... sixfold axis of symmetry 六重对称轴 threefold axis of symmetry 三重对称轴 bifold axis of symmetry 二重对称轴 ...