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: Pacific salmon leave their home stream, swim out to sea and return ____ to six years later to spawn.

SOLUTION: one

PROBLEM: Biological islands are of ____ general types, geographical and ecological.

SOLUTION: two

PROBLEM: Neurologists divide multiple sclerosis into ____ types.

SOLUTION:
two