Two brothers decided to dig a deep hole behind their house. As they were working, some older boys stopped by to watch.

有兄弟俩决定在他们房子后面挖一个深洞。就在他们不停地挖洞时，几个年龄大点的男孩在附近停下来观看。

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The result shows that ultrasonic vibration drilling could improve the working accuracy and efficiency, and could solve the problems exited in the drilling process of small deep hole.

结果显示，该工艺方法能大幅提高小深孔的加工精度和效率，很好地解决了小深孔加工中存在的难题。

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Two brothers decided to dig a deep hole behind their house. As they were working, a couple of older boys stopped by to watch.

有兄弟俩人决定在他们房子后面挖一个深洞。就在他们不停挖洞时，几个年龄大点的男孩在附近停下来观看。

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