As the wood is burned, energy is required to break the bonds in the cellulose.
(the wood; is burned; ) (energy; is required; to break the bonds in the cellulose; T:As the wood is burned) (energy; to break; the bonds; L:in the cellulose)
the wood energy energy
is burned is required to break
to break the bonds in the cellulose T:As the wood is burned
the bonds L:in the cellulose