spanning rail的用法和樣例：
例句
- Each column is equipped in both planes with a preloaded roller bearing guide rail.
每個(gè)立柱的兩個(gè)平面均配有預加載滾柱軸承導軌。 - The welding carriage is adapted to the rails of various diameters,but each rail is adapted to the certain diameter pipe only.
焊接小車(chē)可適應各種直徑的導軌，但每一種導軌只能適應一定的管道管徑范圍。
