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]: Pigs grow very quickly and are normally ready for sale at ____ to six months of age.
[A]: four


[Q]: Sponges are subdivided into ____ classes.
[A]: three


[Q]: Ospreys mature after ____ years of age.
[A]:
two