TASK DEFINITION: In this task, find the most appropriate number to replace the blank (indicated with _ ) and express it in words.
PROBLEM: Pure water contains _ ions and is therefore a nonconductor .

SOLUTION: no

PROBLEM: Women devote their lives to raising families of six, seven and _ children.

SOLUTION: eight

PROBLEM: Most dark colorations begin to lighten after _ weeks of treatment.

SOLUTION:
four