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

[Q]: Least weasels breed one to _ times per year, depending on prey density.
[A]: three


[Q]: Mares generally give birth to one young every _ years.
[A]: three


[Q]: Autism is a neurological disorder that affects _ in every five hundred births.
[A]:
one