( ( ( The key ) ( is ( ( the dispersion ) ( through ( ( the metal ) ( of ( ( carbon compounds ) called ) ) ) ) ) ) ) ( ( ( ( carbides ( that measure ) ) ( ( 3 nanometers ) ( -- ( ( ( 3 billionths ) ( of ( a meter ) ) ) -- ) ) ) ) ( in diameter ) ) . ) )
(ROOT (SINV (S (NP (DT The) (NN key)) (VP (VBZ is) (NP (NP (DT the) (NN dispersion)) (PP (IN through) (NP (NP (DT the) (NN metal)) (PP (IN of) (NP (NP (NN carbon) (NNS compounds)) (VP (VBN called))))))))) (VP (VBZ carbides) (NP (DT that) (NN measure))) (NP (NP (CD 3) (NNS nanometers)) (PRN (: --) (NP (NP (CD 3) (NNS billionths)) (PP (IN of) (NP (DT a) (NN meter)))) (: --))) (PP (IN in) (NP (NN diameter))) (. .)))
The key is the dispersion through the metal of carbon compounds called carbides that measure 3 nanometers -- 3 billionths of a meter -- in diameter.
(ROOT (S (NP (NP (JJ Binary) (NNS compounds)) (PP (IN of) (NP (NP (NN carbon)) (PP (IN with) (NP (ADJP (RBR less) (JJ electronegative)) (NNS elements)))))) (VP (VBP are) (VP (VBN called) (NP (NNS carbides)))) (. .)))