( Subject ( ( matter ( ( in which ) ( ( the ( organo-phosphorus compound ) ) ( contains ( ( ( ( ( a ( heterocyclic ring ) ) ( which ( contains ( ( ( at least ) one ) ( sulfur atom ) ) ) ) ) and ) ( at least ) ) ( ( one ( oxygen atom ) ) ( as ( ring members ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Subject)) (VP (NN matter) (SBAR (WHPP (IN in) (WHNP (WDT which))) (S (NP (DT the) (JJ organo-phosphorus) (NN compound)) (VP (VBZ contains) (NP (NP (NP (DT a) (JJ heterocyclic) (NN ring)) (SBAR (WHNP (WDT which)) (S (VP (VBZ contains) (NP (QP (IN at) (JJS least) (CD one)) (NN sulfur) (NN atom)))))) (CC and) (ADVP (IN at) (JJS least)) (NP (NP (CD one) (NN oxygen) (NN atom)) (PP (IN as) (NP (NN ring) (NNS members))))))))) (. .)))
Subject matter in which the organo-phosphorus compound contains a heterocyclic ring which contains at least one sulfur atom and at least one oxygen atom as ring members.
(ROOT (S (NP (DT A) (JJ heterocyclic) (NN compound)) (VP (VBZ contains) (NP (NP (NNS atoms)) (PP (IN of) (NP (NP (QP (CD two) (CC or) (JJR more)) (JJ different) (NNS elements)) (PP (IN in) (NP (PRP$ its) (NN ring) (NN structure))))))) (. .)))