硬的突起

例句：

1. 1. Therock had a hard protrusion thatmade it difficult to move.
   这块岩石有一个硬突起，使得移动它很困难。
2. 2. The car's bumper hasa hard protrusion that helps protectthe occupants.
   汽车的保险杠有一个硬突起，有助于保护乘客。
3. 3. The tree's trunk has a hardprotrusion that can be usedas a tool.
   这棵树的树干有一个硬突起，可以用作工具。