The tests for the effects of jet position on drag bit cutting process were described.

就射流相对于刀具的四处不同位置对切割效能的影响进行了测试。

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The bit is usually a drag bit fitted with either PDC or natural diamond cutting structures, but the core bit is unusual in that it has a hole in its center.

钻头通常属于刮刀型，装备有PDC或者天然金刚石切削齿，但取芯钻头的特别之处在于钻头中心有一孔。

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And just as their long, heavy trains pose a burden to peacocks, the extravagant feathers of Anchiornis may have been a bit of a drag, literally.

对于雄孔雀来说，硕长且沉重的尾屏是个沉重的负担，而过多的羽毛可能也同样拖累了近鸟龙。

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The third day tends to drag on a bit but we are very happy where we are at the moment.

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Doing that while running to keep up with the crowd could be a bit of a drag.

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This combined with the lag in the population of the guide, makes it a bit of a drag to use.

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