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]: Naiads have ____ caudal filaments and external gills.
[A]: two


[Q]: Threshold is a value to avoid ____ divide.
[A]: zero


[Q]: Women taking vitex for ____ months appear to have more success at becoming pregnant.
[A]:
three