我摘黑莓的时候手指被刺扎到了。

I pricked my finger on the ___bur while picking blackberries.

打磨金属时，记得清理掉切割后留下的毛刺。

When polishing metal, remember to remove the ___burr left after cutting.

牙医正在用钻头清理我牙齿上的蛀洞。

The dentist is cleaning the cavity in my tooth with a small ___bur.