First it marked out a race-course, in a sort of circle, ('the exact shape doesn't matter, ' it said, ) and then all the party were placed along the course, here and there.

首先，它划出个比赛路线，有点像个圆圈，它说：“具体形状没关系的。”

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One of the problems that has never been solved is that of "squaring the circle." This really means to find the exact area of a circle.

一个一直没有得到解决的问题是，怎样“求圆的面积”。这个问题的真实意思是：求一个圆的精确面积。

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By focusing a circle of light on the cornea and measuring its reflection, it is possible to determine the exact curvature of the cornea's surface.

通过将一束圆形光圈聚焦在角膜上，测量反射过来的光线，就能得出角膜表面曲率的确切数据。

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