Answer:
Two in a whole and four in a pair. Six in a trio you see. Eight's a quartet but what you must get is the name that fits just one of me.
I tell people to be careful when handling boxes.
I am free the first time and the second time, but the third time is going to cost you money. What am I?
I have an eye but cannot see. I am fast but I have no limbs. What am I?
Use me if you really want to see inside someone
No matter how little or how much you use me, you change me every month.
What am I?
Animal
Difficult
Easy
Food
Funny
Kids
Logic