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: Divorce affects one out of every ____ marriages today.

SOLUTION: four

PROBLEM: Photons have no mass and ____ electrical charge.

SOLUTION: no

PROBLEM: Natural samarium is a mixture of seven isotopes, ____ of which are unstable with long half-lives.

SOLUTION:
four