Let's consider four levels of a generic operation.

让我们考虑一个通用操作的四个步骤。

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So you have to drill down four levels to get the data.

因此，为了获取数据，必须深入4层。

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Both figures show the four levels of the example process.

两个图都显示了示例流程的四个级别。

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The four levels of rooms center on a beautiful courtyard with a glass ceiling to let light shine in.

VOA: special.2009.01.11

At some point, maybe a week later, four to eight days later, you would start to see antibody levels rise.

之后,或许一周之后,四天到八天之间,就可以看到抗体的浓度开始上升

耶鲁公开课 - 生物医学工程探索课程节选

So we have four choices in terms of initial and final energy levels, and also what it means - in terms of the electron -- whether it's gaining energy or whether it's going to be emitting energy?

我们有这四个选项,各有不同的初始能量和末能量,它都是按照电子来说的,不管是失去能量还是得到能量？

麻省理工公开课 - 化学原理课程节选

The 23 rooms are spread over four levels and exhibit thousands of exquisite figurines that Rivera wanted preserved.

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There are four levels of participant with varying degrees of access: main, admin, topic admin, and contributor.

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"I've talked to Thai workers who are three or four levels down from the original orders, " he says.

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