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]: Brook stickleback have prominent mouths, large eyes and ____ to six spines on their backs.
[A]: four


[Q]: Calves are born after a gestation of ____ months.
[A]: nine


[Q]: Captive females begin to mate at eight or ____ years of age.
[A]:
nine