protrusion of surface

例句：

1. 1.The rock is a natural protrusion from the mountainside.
   这块岩石是山体自然突出的部分。
2. 2. The surgeon carefully removed the protrusion without causing any damage to the surrounding tissue.
   外科医生小心翼翼地切除了这个突出部分，没有对周围的组织造成任何伤害。
3. 3. The protrusion of the horns on the animal's head was an indication of its aggressive nature.
   动物头上的角突出表明了它的攻击性。