You hook one end of the spring to a wall and you pull it from rest by some amount and you attach the one kilogram mass to it.

你把弹簧的一端固定在墙上,然后拉伸一段距离,接着你把 1 千克物体固定在上面

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You know what? I forgot to hook it up.

哦,我忘记把它连上了

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And in fact, you can take the wire, the electrode, and hook it up to a lever and teach the rat how to push the lever and give itself a little burst of pleasure.

事实上可以把电线，电极，连接到一个杠杆上，教老鼠,推动杠杆获得快感。

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