把一段绳子绕在柱上，或绕在棒子上，可以利用绳子，和柱子间的摩擦力，达到我们想要的，它是如此运作的。

You wrap a rope around a pole, or around a rod, and you use the friction between the rope and that rod to your advantage, and it works as follows.

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把绳子环绕在柱子上。

Loop the rope around the pole.

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把绳子环绕在柱子上。

Loop the rope around the gate.

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把绳子环绕在柱子上。

Loop the rope around the gate.

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