Answer:
I have two body parts but am used to measure length. What am I?
I am long and slim works in light. Has but one eye and an awful bite.
I cover what's real; hide what is true, but sometimes bring out the courage in you. What am I?
I have a brother. However much we run we do not reach each other.
Draw fire or fill me; I'm still empty.
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.