TASK DEFINITION: In this task, find the most appropriate number to replace the blank (indicated with _ ) and express it in words.
PROBLEM: Prolactin exists in _ heterogenic forms which possess varying biological activity.

SOLUTION: three

PROBLEM: Sprawl destroys _ million acres of farmland every two years.

SOLUTION: one

PROBLEM: Raindrops produce _ types of sound underwater.

SOLUTION:
two