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: Numbers can be positive or ____ only.

SOLUTION: zero

PROBLEM: Mollusks have one or ____ hearts.

SOLUTION: two

PROBLEM: Tropical trees can be rampant growers, and can outgrow a wiring in as little as ____ days' time.

SOLUTION:
ten