The indifference curve may be compared with a contour line on a map. 无差别曲线可以与地图上的等高线相比拟。
Are strips of a mouth thickness and back thickness basic indifference, to guarantee the binding of skinpass intervetebral collers. 均能做到裁口厚度和书背厚度基本无差别，保证了胶订书刊外型的平整美观。
