TASK DEFINITION: In this task, find the most appropriate number to replace the blank (indicated with _ ) and express it in words.
PROBLEM: Planaria has rudimentary eyes which produce _ images but detect direction.

SOLUTION: no

PROBLEM: House wrens are small birds, four and a half to _ and a four inches in length.

SOLUTION: five

PROBLEM: Giraffes have two horns and two or _ knobs.

SOLUTION:
three