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

[Q]: Rodents have _ toes on their front feet and five on the hind feet.
[A]: four

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

[Q]: Cats have five toes on the forefeet and _ on the hind feet.
[A]:
four