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

Q: Females reach sexual maturity around four to _ year-olds.

A: five
****
Q: Trees can also be air layered but air layering usually takes four to _ months to be successful.

A: six
****
Q: Most women notice their breasts become fuller and firmer within the first _ to eight weeks.

A:
six
****