Given a sentence, fill out the missing word with a 'no' or a number (between zero and ten). You should write the numbers with english alphabet, like: four instead of 4.

Q: Sexual maturity occurs at ____ to four years for females and four to five years for males.

A: three
****
Q: Rattlesnakes breed only every ____ to three years.

A: two
****
Q: Summer is the hottest of the ____ temperate seasons , falling between spring and autumn .

A:
four
****