Looks as if it was made by a sharp edge of something in metal.

看起来好像是什么金属东西的锋利边缘割的。

Be careful—it has a sharp edge.

小心点—这刀刃很锋利。

This picture echoes an old Chinese poem: Sharp edge of a sword comes out from grinding, and plum blossom's fragrance comes from the bitter cold.

这张照片和一首中国古诗产生了共鸣：宝剑锋从磨砺出，梅花香自苦寒来。

A sharp edge on a rock face.

岩面上锐利的小把手点。

The sharp edge of irregular teeth.

边缘有不规则的尖齿。