sunken arc的意思|示意

The arc-shaped concave of the sunken part of the pillow, can effectively solidify the bone growth, and prevent the part of head resting on the pillow getting bald;

枕头的凹部的弧形凹陷可以起到对孩子的头部骨骼定型的作用，有效预防枕秃的现象；

On both end of the arc are sunken spaces which extend the public square into the buildings naturally.

建筑两端的下沉空间，使步行广场自然向下延伸。