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]: Amphibians are the first true vertebrates with ____ limbs.
[EX A]: four

[EX Q]: Natural ytterbium is a mixture of ____ stable isotopes, with seven other unstable isotopes known.
[EX A]: seven

[EX Q]: Guillemots are fed sprats three or ____ times a day and are constantly checked by vets.
[EX A]:
four