But if be hind the stair of treatment, the space is fixed, and the fittings dimension of stair also is prefab, sure existence is worn between two fixed dimension contradictory.

• 但假如是后加工的楼梯，空间是固定的，而楼梯的配件尺寸也是预制的，两个固定的尺寸之间必定存在着矛盾。