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

[EX Q]: Fire extinguishers have _ parts.
[EX A]: seven

[EX Q]: Infertility affects one in _ couples and affects both men and women.
[EX A]: seven

[EX Q]: Counterpoint is the simultaneous combination of _ or more melodies.
[EX A]:
two