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: Birds have ____ beak, two wings, and two feet.

A: one
****
Q: Herbs require at least ____ hours of sunlight.

A: six
****
Q: Salicylic acid has a half life of about ____ hours at therapeutic doses.

A:
four
****