The single file line snaked slowly and the candidates handled the break differently.
As we were climbing out of the valley, the trail narrowed to single file.
We go in single file, crunching through the leaves, dodging broken bottles and jutting rocks with our bare feet.
Even show ponies are not exempt from ending up in a narrowing chute that feeds the condemned in single file into the “stun box.”
An enemy could only approach down that narrow path in single file.
Jan followed, and the other men fell in behind in single file.
The ladies walked in single file, about eight feet apart, each holding the train of the one preceding her.
A convoy of canoes, thirty in number, in single file, formed this wonderful funeral procession.
We now perceived that a company of Prussians were advancing in single file down the Quai towards us, and were entering the houses.
They had but just established their camp, when they saw six savages approaching, following each other in single file.