( Subject ( ( matter ( ( in which ) ( ( the ( organo-phosphorus compound ) ) ( contains ( ( a ( heterocyclic ring ) ) ( which ( contains ( ( ( ( at least ) one ) ( sulfur atom ) ) ( as ( a ( ring member ) ) ) ) ) ) ) ) ) ) ) . ) )
(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 (DT a) (JJ heterocyclic) (NN ring)) (SBAR (WHNP (WDT which)) (S (VP (VBZ contains) (NP (NP (QP (IN at) (JJS least) (CD one)) (NN sulfur) (NN atom)) (PP (IN as) (NP (DT a) (NN ring) (NN member)))))))))))) (. .)))
Subject matter in which the organo-phosphorus compound contains a heterocyclic ring which contains at least one sulfur atom as a ring member.
(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))))))) (. .)))