TASK DEFINITION: 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.
PROBLEM: Cytochrome oxidase consists of two cytochromes and ____ copper atoms.

SOLUTION: two

PROBLEM: Babies crawl into a pouch on the mother's belly and stay there ____ months.

SOLUTION: four

PROBLEM: Protein synthesis occurs in ____ generally recognized stages.

SOLUTION:
four