Okay, so the key here is going to be that there are two passes.

好了,这里的关键问题是有两条路

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And there's two you could use to attack through, easy or hard.

同样他也有两条路入侵途径,平坦之途和崎岖之途

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Now this isn't the first time in this course that I've paused over a moment at a crossroads where you can't possibly take both paths but where it is obviously very, very difficult to make up one's mind.

现在是这个课程中第一次,在一个分叉路口停下,我们不可能同时走两条路,但是这也显然是非常难以决定的一个地方。

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So imagine the following example, an invader is thinking about invading a country, and there are two ways -- there are two passes if you like -- through which he can lead his army.

想象一下这样的例子,一个侵略者打算入侵一个国家,有两条路,想象成两个关口也行,侵略者必须通过一个才能进入

耶鲁公开课 - 博弈论课程节选