Answer:
I dig out tiny caves and store gold and silver in them. I also build bridges of silver and make crowns of gold. Sooner or later everybody needs my help yet many people are afraid to let me help them.
Keep doing me to avoid lens dryness
The more you add the less it weighs. What is it?
I help you carry your books.
I dance on one feet and knows only one shape. Someone with same name as me is very good with directions
Give it food and it will live, give it water and it will die.