a north-south railway line的用法和样例：
- The train moves a long the railway line or track.
- You will be in dangerif you walk on a railway line.
- A north wind was blowing hard last night.
- The railway line follows the river for several miles.
- The railway line was closed because of (a) subsidence.
- Shanghai South Railway Station of Metro Line 1 was moved entirely in 2004.