In this task, find the most appropriate number to replace the blank (indicated with _ ) and express it in words.

[EX Q]: Vitamins are classified into _ groups.
[EX A]: two

[EX Q]: Skin cancer affects one in _ people in the United States over a lifetime.
[EX A]: six

[EX Q]: Children range in age from birth to _ years.
[EX A]:
six