Answer:
What starts with an "e" but only has a single letter in it?
It is a gruesome form of betray.
What get's more wet while it dries?
If you are unsure how to use one then just ask a flight attendant.
What instrument can make any sound and be heard but not touched or seen?
Though not a plant, has leaves. Though not a beast, has spine. Though many wouldn't need this thing, It's more valuable than wine.