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: Prions are protein molecules which have ____ metastable states.

SOLUTION: two

PROBLEM: Most bacteria have one or ____ circular chromosomes.

SOLUTION: two

PROBLEM: Sharks have ____ different types of fins.

SOLUTION:
five