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

[Q]: Dairy cows live for _ generations, calve and produce normal milk on a protein-free diet.
[A]: six


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


[Q]: Basal cells regenerate the _ other cell types.
[A]:
two