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: Females usually reach sexual maturity at about four years of age, males at about ____ years.

SOLUTION: six

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

SOLUTION: three

PROBLEM: All species have ____ basic requirements for survival.

SOLUTION:
four