With the increase of the train running speed, the requirements on the smoothness of the rails have become more and more strict.

随着行车速度的提高，对轨道的平顺性要求愈加严格。

youdao

With the increase of the train running speed, the requirements on the smoothness of the rails have become more and more strict.

随着行车速度的提高，对轨道的平顺性要求愈加严格。

youdao