bolt rails

例句：

1. 1.The bolts holding the roof in place are rusted and need to be replaced.
   固定屋顶的螺栓生锈了，需要更换。
2. 2.The rails on the train were damaged during the accident.
   火车上的轨道在事故中受损了。
3. 3. The bolts holding the door shut were too tight and caused discomfort.
   固定门的螺栓太紧了，导致不适。