horseshoe nail

例句：

1. 1.He used a horseshoe nail to fix the door.
   他用马蹄铁钉固定了门。
2. 2.The horseshoe nail was rusted and couldn't hold the door shut.
   马蹄铁钉生锈了，无法把门关上。
3. 3.The old horse had a horseshoe nail in its mouth.
   老马嘴里有一颗马蹄铁钉。