In this task, find the most appropriate number to replace the blank (indicated with _ ) and express it in words.

[EX Q]: Cities have various sizes, and can contain from _ to four armies depending on size.
[EX A]: one

[EX Q]: Most amphibians reach maturity at three or _ years.
[EX A]: four

[EX Q]: Larval tunicates are free swimmers and possess all _ chordate characteristics.
[EX A]:
four