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

Q: Rams can be policerate, often producing _ horns.

A: four
****
Q: Some people routinely sleep only _ hours a night but feel fine during the day.

A: four
****
Q: Inversions have the classic double loop at meiosis, and have _ crossovers when heterozygotes.

A:
no
****