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: Hoatzin has typical foot with ____ toes forwards and one backwards.

SOLUTION: three

PROBLEM: Wood consists of ____ distinct fuels.

SOLUTION: two

PROBLEM: Radioactive waste is deposited in ____ concrete tanks within a fenced area.

SOLUTION:
four