Something to Remember

Question: What's cheaper than gold, yet more valuable.Hard to find, but easy to loose

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

Question: What tastes better than it smells?

Question: What goes in the water black and comes out red?

Question: What asks but never answers?

Question: There is an ancient invention still used in some parts of the world today that allows people to see through walls.What is it?