关于数据项uid的一个要点—它们并不总是保持不变。

One important thing to note about data item uids-they don't always stay the same.

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频道中的其他元素可能不变，但项经常发生变化。

While other elements within a channel may stay constant, items are likely to change frequently.

youdao

当然，函数的二阶项，可以看出，实际上发生了变化的，函数并不是真的不变了。

Then, of course, there will be maybe quadratic terms that will actually turn that, you know, this won't really say that your function is actually constant.

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