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]: Traffic lights have ____ colors.
[A]: three


[Q]: Insomnia can be short-lived, lasting only one to ____ nights.
[A]: two


[Q]: Most spiders have ____ eyes, but some have fewer.
[A]:
eight