TASK DEFINITION: In this task, find the most appropriate number to replace the blank (indicated with _ ) and express it in words.
PROBLEM: Pollination is accomplished only by insect-agency, and where insects fail _ fruits are ripened.

SOLUTION: no

PROBLEM: Light falls on a _ dimensional object and creates a shadow.

SOLUTION: three

PROBLEM: Sulfur plays _ important roles in global change biology.

SOLUTION:
two