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: Infertility affects one in ____ couples today.

A: five
****
Q: Threshold is a value to avoid ____ divide.

A: zero
****
Q: Voles are prolific breeders and can produce ____ to six litters a year.

A:
four
****