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.

Brook stickleback have prominent mouths, large eyes and ____ to six spines on their backs.
four

Cellulose contains nothing that is considered hazardous, and carries ____ hazardous warning messages.
no

Digoxin works in ____ ways.

two