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: Tin has ____ allotropic forms.

SOLUTION: two

PROBLEM: Hydroplanes have ____ or more wetted surface areas.

SOLUTION: two

PROBLEM: Alligator gars have ____ rows of teeth.

SOLUTION:
two