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]: Crustaceans have ____ pairs of antennae.
[EX A]: two

[EX Q]: Most organ systems are operational in the fetus by ____ to six months.
[EX A]: four

[EX Q]: Grasshoppers develop through ____ to six instars.
[EX A]:
five