TASK DEFINITION: In this task, find the most appropriate number to replace the blank (indicated with _ ) and express it in words.
PROBLEM: Frozen grafts can have a shelf life of up to _ years.

SOLUTION: five

PROBLEM: Carbon dioxide accounts for _ fourths of the predicted increase in the greenhouse effect.

SOLUTION: three

PROBLEM: Any closed figure formed by _ or more line segments is called a polygon .

SOLUTION:
three