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

Q: Pelycosaurs are a paraphyletic group of _ primitive families of synapsids.

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

A: six
****
Q: Unconsciousness can take place within one to _ minutes.

A:
two
****