The contour lines on the map indicate the elevation of the land.

The color line refers to the discrimination between white and black people.

The production line at the factory is highly efficient.

The ball landed just outside the foul line.

The fault line runs through the entire region, causing frequent earthquakes.

I need to get in line for the concert.

The soldiers formed a battle line and prepared for the attack.

We have to draw a line somewhere.

The assembly line is an efficient method of production.

I merged onto the highway using the acceleration line.