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: Tin exists in ____ allotropic forms.

SOLUTION: three

PROBLEM: Some people routinely sleep only ____ hours a night but feel fine during the day.

SOLUTION: four

PROBLEM: Athematic verbs have a full grade root under stress, but a ____ grade when the ending is stressed.

SOLUTION:
zero