Actually, the operation of plain bearings doesn't involve metal to metal contact!

实际上轴承运转时不涉及金属对金属的接触！

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The results showed that the principal factors affecting the metal background contents were landforms for plain area and soil parent material for mountain area.

分析结果表明，影响土壤元素背景值的主要因素，在平原地区是地貌条件，在山区是成土母质。

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There were troops with machine guns checking the credentials of officials and reporters, in addition to plain-clothes security officials with more familiar metal detectors.

军人荷枪实弹检查官员和记者是否安全，便衣安全人员也带着金属探测器。

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Consider refinishing the walls in sheetrock, diamond plate metal or plain corrugated sheet metal.

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At the back of Weird Stuff store, Williams spots a plain metal box.

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The result is that the pitted tungsten becomes much hotter than a plain sheet of the metal could manage.

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