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: Photons have ____ mass and no electrical charge.

SOLUTION: no

PROBLEM: Most people stay three or four years, sometimes five or ____ years.

SOLUTION: six

PROBLEM: Hippos have ____ webbed toes on each foot and typically reside in slow-moving or still waters.

SOLUTION:
four