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

[EX Q]: Premolars have one, two, and sometimes _ canals.
[EX A]: three

[EX Q]: Calves grow quickly and are weaned from their mothers in only _ to four months.
[EX A]: three

[EX Q]: Life is manifest in _ distinct states of existence.
[EX A]:
four