main line section的意思|示意

A crontab line contains two main sections, a time schedule section followed by a command section.

一个crontab行包括两个主要部分，即时间调度部分及其后接的命令部分。

And the dynamic characteristics of trains flow in speed limit section of main-line railway are analyzed.

随后对干线铁路中限速区段交通流的特性进行了分析。

It's one of the main machines in the modern pipe mill line and formed section line.

它是现代高频直缝焊管生产线和冷弯型钢生产线的主要设备之一。