And as I'm going to do many times in 3.091, I'm going to start a unit like this with a history lesson.

在3。091这门课上我会重复很多次，我会像现在一样以一个历史的故事,来开始新的一单元。

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It also is a good lesson in how difficult it is, and we'll talk about this in a subsequent class, to actually measure what people eat.

同样这能很好的说明,实际评价人们的饮食有多困难,我们下节课会讨论这个话题

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In a sense, this is the first difficult lesson of the class.

这是这门课第一个较难的结论

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That's a very important lesson to keep in mind.

这一点非常重要,要牢记心中

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Then much later on, when we looked at some more complicated payoffs and a more complicated game, we looked at a different lesson which was this: put yourself in others' shoes to try and figure out what they're going to do.

在这之后我们通过研究更复杂的收益,以及更复杂的博弈,我们得出了另外一个结论,站在别人的立场去思考,他们会怎么做

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