Plane is the mechanical base of geometrical accuracy and a lot of references such as plate, level and square, etc. are evolved from the plane.

几何精度的机械技术基础是平面，由平面可演变出基准平尺、平板、方尺等精度基准。

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Plane is the mechanical base of geometrical accuracy and a lot of references such as plate, level and square, etc. are evolved from the plane.

几何精度的机械技术基础是平面，由平面可演变出基准平尺、平板、方尺等精度基准。

youdao