I could not bring myself to change a single line of the plan.

Each side was a single line, with no more than one man every ten feet.

Because it's a single line, only one way can run all the time.

It is a single line, and nothing could have passed.

Nor could she remember a single line after it was gone.

However, there is not a single straight line in the building.

She allowed herself just a single line, enough to take the edge off.

Cast off and hold her ready on a single line.

Match all five numbers on a single line to win $200,000.

In other words they were really double, not single lines.