Answer:
What goes through a door but never goes in and never comes out?
I'm a starchy plant tuber that is one of the most important food crops, cooked and eaten fried, such as french fries.
The buyer doesn’t want it, the producer doesn’t need it and the user doesn’t know their using it.
What kind of room doesn't have physical walls?
What has no hands but might knock on your door, and if it does you better open up?
Which bank is not used for storing money?