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

[EX Q]: Most children start to get their adult teeth at about _ years of age.
[EX A]: six

[EX Q]: Most people go back to work within _ to three months after having a heart attack.
[EX A]: one

[EX Q]: Photons have _ mass or charge, but are electromagnetic, as are light, uv, and radio waves.
[EX A]:
no