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: Ferrets normally tremble for ____ reasons.

SOLUTION: two

PROBLEM: Sponges have ____ main tissue layers.

SOLUTION: three

PROBLEM: Territorial groups consist of one supermale or terminal male and one to ____ females.

SOLUTION:
three