History has to follow main lines or the story would never be told.

It has never been one of the main lines against 1.

The main line through here was closed on 5 May 1969.

Right, it is not the main line of the play.

The real battle will not be decided along the main line but rather here.

There were two main lines of thought I could follow.

The main line between the two cities opened in 1903.

It's more likely that they took the main lines down, outside of town.

Actually there is no strong reason for thinking that the main lines of development would have been very different.

But I can hardly be wrong about the main lines.