Riddle #43

Question: I am taken from a mine, and shut up in a wooden case, from which I am never released, and yet I am used by almost everybody.

What am I?

Question: What do you call a sad bird?

Question: What kinds of balls do dragons play soccer with?

Question: What has a bed that you can't sleep in?

Question: How are doughnuts and golf alike?

Question: What cannot be seen or felt, but can only be broken by voice?