EXAMPLES FROM THE WEB FOR SINGLE FILE
The trail was very narrow in places, so that they had to walk in single file.
A moment later three men walked, single file, into the room.
There was only just room to do so in single file, and I went first with the lantern.
Behind him in single file, imitating his step, marched the other Indians.
Jan followed, and the other men fell in behind in single file.
We will walk in single file; I in front of you, and Fred behind you.'
I led off, and Captain Rudstone and Carteret followed in single file.
A convoy of canoes, thirty in number, in single file, formed this wonderful funeral procession.
They had but just established their camp, when they saw six savages approaching, following each other in single file.
Five Indian warriors walking in single file were approaching.