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: Green energy comes in ____ basic forms.

SOLUTION: two

PROBLEM: Raindrops produce ____ types of sound underwater.

SOLUTION: two

PROBLEM: Fusion energy is released when ____ small atoms merge together.

SOLUTION:
two