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 reached at ____ years, and females calve every other year.
four

Sealants can normally last up to ____ years and hold up very well under normal chewing.
five

Insects develop from an egg into an adult in ____ ways.

three