TASK DEFINITION: In this task, find the most appropriate number to replace the blank (indicated with _ ) and express it in words.
PROBLEM: Allergic rhinitis is the most common allergic disease, with one in _ Canadian adults affected.

SOLUTION: five

PROBLEM: Chlorine is manufactured in _ ways.

SOLUTION: two

PROBLEM: Space is a configuration of _ 'immaterial particles'.

SOLUTION:
four