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.

Sexual maturity is between ____ and six years of age.
three

Hypertension afflicts about ____ in four American adults, both men and women, of all ages.
one

Volcanic islands move through ____ stages of growth and erosion.

eight