Pick a time. Let's say, if I go a quarter of a circle, I expect to be moving to the left.

选一个时间,例如我走四分之一圈,我想向左走

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I've got to tell you whether I went to the right or whether I went to the left.

我必须告诉你,我是向右走还是向左走的

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But, you know, in 2D, the options are not just left and right or north and south, but infinity of possible directions in which I could go those 5 km.

但在二维空间中,不仅可以向左向右或者向南向北,我在走那5公里的时候可以有无数个方向

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