TASK DEFINITION: In this task, find the most appropriate number to replace the blank (indicated with _ ) and express it in words.
PROBLEM: Most people stay three or four years, sometimes _ or six years.

SOLUTION: five

PROBLEM: Morocco has _ perennial rivers and many dams have been built with potential for power generation.

SOLUTION: four

PROBLEM: Sweet potatoes have _ basic flesh types, dry or moist.

SOLUTION:
two