One, two, three ... three times at the other ... so eight specific actions by him, knocking it with another stone, to take off a flake, and to leave this almost straight line, which is a sharp edge.

所以他不多不少恰恰打了八次，利用其他石头来打磨它，敲掉一小薄片，留下这边面几乎呈现直线，边缘相当之锋利。

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To make clean straight folds in cardboard, first make a crease along the line with a blunt edge such as a spoon handle, then fold against a firm straight edge.

为了使清洁直纸板折叠，先如勺子处理沿钝边行折痕，然后对折直边坚定。

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From the side, the front line is perpendicular and straight, coinciding with the maxillary edge or slightly projected forward.

从侧面看，前行是垂直而直，与上颌骨边缘或稍向前预测相吻合。

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To create a faux molding, a straight edge and pencil are used to draw a line, then shading is added with paint to give the look of a curve.

WSJ: An Artisan Who Can Turn Paint into Stone | Creating