No flat surface perpendicular to the pseudo-twofold axis could be formed. 不能自然形成垂直于伪二次轴方向的平坦的表面小平面。
The long axes of the ellipsoidal shaped calcareous concretion reflected the direction of movement of mineralizing groundwaters. 椭圆形的钙质结核的长轴方向反映了地下矿化水的流动方向。