TASK DEFINITION: In this task, find the most appropriate number to replace the blank (indicated with _ ) and express it in words.
PROBLEM: Animals develop either two or _ embryonic germs layers .

SOLUTION: three

PROBLEM: Most people go back to work within _ to three months after having a heart attack.

SOLUTION: one

PROBLEM: Unsafe acts cause _ times as many accidents as unsafe conditions.

SOLUTION:
four