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: Pathologists study four to ____ years after medical school and their postgraduate training.

SOLUTION: five

PROBLEM: Cichlids are popular in the aquarium hobby for a ____ reason.

SOLUTION: four

PROBLEM: Some prisons house up to ____ times their capacity.

SOLUTION:
seven