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: Some children start asking questions when they're ____ or five years old.

A: four
****
Q: Corporate mergers occur when ____ companies combine.

A: two
****
Q: Most gymnasts practice twice per day for at least ____ hours per session.

A:
three
****