So, what happens is the UCS and the CS, the bell and the food, go together because they happen at the same time.

发生的事情不过是,无条件刺激与条件刺激，铃声与食物，因为恰巧同时出现而联系在了一起。

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Well, when Pavlov, for instance, started before conditioning there was simply an unconditioned stimulus, the food in the mouth, and an unconditioned response, saliva.

比如，在条件作用形成之前,只是简单的存在着无条件刺激，即食物，以及无条件反应，即唾液。

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