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

[EX Q]: Some dentists prefer using the oral rinse for _ to five days at a time.
[EX A]: three

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

[EX Q]: Toxic pollutants come from _ main sources, agriculture and industry.
[EX A]:
two