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

[Q]: All insects have _ pairs of legs and adult wings.
[A]: three

[Q]: Full sun is classified as any area that receives a minimum of _ hours of direct sunlight each day.
[A]: six

[Q]: Tornado intensity is measured on a scale of _ to five, with five the strongest.
[A]:
zero