TASK DEFINITION: In this task, find the most appropriate number to replace the blank (indicated with _ ) and express it in words.
PROBLEM: Immune response improves in about _ weeks.

SOLUTION: four

PROBLEM: Gerbils get reproductive when they reach sexual maturity at the age of _ months.

SOLUTION: three

PROBLEM: Weeds become more abundant after _ or more rice crops.

SOLUTION:
two