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: Some airports have ____ parallel runways.

SOLUTION: two

PROBLEM: Coho usually live for ____ years and grow rapidly in their final year.

SOLUTION: three

PROBLEM: Sulfur exists in ____ allotropic forms.

SOLUTION:
two