这种测试由固定的分等级系列的不完整环的间隙组成，这些环的径向厚度和间隙为环的直径的五分之一。
The test consists of locating the gaps in a graduated series of sizes of incomplete rings whose radial thickness and gap are equal to one-fifth the diameter of the ring.
我完全可以理解试图要求别人接受这样的考验进入一个系列的威胁等级。
I can completely understand the level of intimidation in trying to ask someone to undergo such a trial to get into a series.
在Eclipse系列中的书籍是面向不同等级的技术人员。
The books in the Eclipse series are pitched to various levels of technical expertise.
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