Answer:
What two things can you never eat for breakfast?
Two in a whole and four in a pair. Six in a trio you see. Eight's a quartet but what you must get is the name that fits just one of me.
In buckles or lace, I help set the pace. The farther you go, the thinner I grow. What am I?
I am easy to waste and unstoppable. What am I?
I am there when you sit, but gone when you stand. What am I?
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.