Answer:
It's equally comfortable in an orchestra and a geometry textbook. What is it?
What goes up but never comes down?
What I am filled, I can point the way. When I am empty. Nothing moves me. I have two skins. One without and one within.
People like this usually live in rural areas, unless they are lucky enough to strike oil and move to Beverly Hills.
What English word retains the same pronunciation, even after you take away four of its five letters?
Keep doing me to avoid lens dryness