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

[EX Q]: Many Asian countries deny entry to travelers whose passports are valid for less than _ months.
[EX A]: six

[EX Q]: Packs usually have fewer than _ wolves.
[EX A]: ten

[EX Q]: Presidential elections occur once every _ years.
[EX A]:
four