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.

Respiratory therapists complete two to ____ years of education.
four

Orchestra conductors live ____ to seven years longer than is usual in their societies.
three

Flowers are usually bisexual and have ____ petals but have sepals that mimic petals.
no