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

[Q]: Pets also track in pollen, and _ out of every ten people is allergic to cat or dog dander.
[A]: one


[Q]: Some herbaceous plants live only five to _ years.
[A]: six


[Q]: Alcohol is the _ common factor in the four leading causes of death in teens.
[A]:
one