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

[EX Q]: Most divorces take place after three to _ years of marriage.
[EX A]: five

[EX Q]: Men produce brand new sperm every _ to three months.
[EX A]: two

[EX Q]: Biologists recognize _ styles of partnership in nature.
[EX A]:
four