a main-line station的用法和样例：
- An additional telephone connected to a main line.
- To analyze its deep connotation, it is necessary that take interest coordination as a main line to impenetrate in it.
- The game is along a main line of development, weapons, heroes, must complete the task and the need to resist the opponent.
- There is a main line is always worth the investment by investors, it is the turn up, warming up the Shanghai local Biao shares.
- A type of stitch in which short stitches project at right angles from a main line of stitching formed similarly to coiling. Also known as ray stitching.