In this task the focus is on physical knowledge about the world. Given the provided goal task in the input, describe a process that would lead to the asked outcome. This process often involves physical motions with objects, such as moving them, arranging them in a certain way, mixing them, shaking them, etc. 

To test batteries to see if they're any good,
drop the batteries and see if they bounce once to see if they're good.

How do I inflate a helium balloon
You will need to go buy a helium tank, then attach the balloon to it and press the button

What is the best size for a napkin holder?

The napkin holder need only be small and handy, so that it can be placed on a convenient spot.