There's something else about smiles which is going to come up, which your question raises, I think, which is going to come up in when we talk about emotional contagion and actually, some issues of morality.

其他与微笑有关的话题开始浮现了，你提出问题，我想，可能出现,当我们讨论情绪感染时，事实上，一些道德话题。

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