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.

[EX Q]: Some tropical species have ____ or three generations per year.
[EX A]: two

[EX Q]: Respiratory therapists complete two to ____ years of education.
[EX A]: four

[EX Q]: Fathers invest in shoes for feet that mature in ____ weeks.
[EX A]:
six