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: Tall fescue produces the ____ diazaphenanthrene alkaloids, perlolidone and perloline.

SOLUTION: two

PROBLEM: Amphibians are the first true vertebrates with ____ limbs.

SOLUTION: four

PROBLEM: Retirement pay is based on the average of the highest ____ years of pay.

SOLUTION:
three