We need to set a base-line to measure our current performance against.

I don't like waiting in line for a long time.

It is important to toe the line and follow the rules.

I need to get in line for the concert.

We have to draw a line somewhere.

I'm sorry, I have another call on the other line. Can I call you back later?

Our troops managed to infiltrate the enemy line.

The Mason Dixon line separates the northern and southern states in the United States.

The International Date Line marks the boundary where each calendar day begins.

I go down the line for my favorite sports team.