Answer:
Useful term for when you need to start a fire or notice someone with the same shirt as you.
What word becomes shorter when you add two letters to it?
Soldiers fight it but never changes.
What pulls you down and never lets go?
It is a common and favored clothing material among biker gangs and superheroes.
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.