这是因为CAD系统需要准确的规格和精确地尺寸来建立几何图形，尽管这些细节可能是不必要的，而且这些在概念设计阶段往往是不清楚的。

This is because CAD systems require exact sharp specification and dimensions for geometry creation even though these details are probably unnecessary and often unknown at the concept design stage.

youdao

这是因为CAD系统需要准确的规格和精确地尺寸来建立几何图形，尽管这些细节可能是不必要的，而且这些在概念设计阶段往往是不清楚的。

This is because CAD systems require exact sharp specification and dimensions for geometry creation even though these details are probably unnecessary and often unknown at the concept design stage.

youdao