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

[EX Q]: Aquatic adults have prominent red reathery gills, are large, and have _ toes on each foot.
[EX A]: four

[EX Q]: Cluster flies are covered with fine golden hairs and have _ stripes on the thorax.
[EX A]: no

[EX Q]: Measurable snow falls only once every three or _ years.
[EX A]:
four