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

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

[Q]: Urushiol oil can be active on any surface for _ years and possibly longer.
[A]: five

[Q]: Teenage boys are _ times more likely to become regular drug users than girls.
[A]:
three