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: All ticks have ____ pairs of legs during the immature stage and four pairs as an adult.

SOLUTION: three

PROBLEM: Most organ systems are operational in the fetus by ____ to six months.

SOLUTION: four

PROBLEM: Biennials live ____ years.

SOLUTION:
two