提示：点击例句中的单词，就可以看到词义解释

An instruction that causes the program to branch from the mainline program to the starting address of a subroutine .

使程序由主程序转到子程序的起始地址的指令。

While it has bought non-boeing planes for its American Eagle regional jet fleet , American , as its name suggests , prefers American-made aircrafts for its mainline fleet .

尽管美国航空公司也曾为其旗下美国之鹰航空（AmericanEagle）购买过用于区域运输的非波音机型飞机，但美国航空，顾名思义，将首选美国制造的飞机作为其干线运营机型。

The project X codeline was spawned from the mainline .

项目X的代码线衍生自主线。

Instead , changes in team A work should flow to the mainline and then down to team B work .

实际上，在团队A工作分支中发生的变更应该流回到主线中，再向下进入到团队B的工作分支中。

He took a taxi straight to the mainline station .

他乘了辆出租车直接驶往铁路干线上的那个车站。