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: Infertility affects one in ____ couples today.

SOLUTION: five

PROBLEM: Pacific salmon leave their home stream, swim out to sea and return ____ to six years later to spawn.

SOLUTION: one

PROBLEM: Ovulation failure accounts for ____ in five cases, as do blocked or diseased fallopian tubes.

SOLUTION:
one