( ( Fresh ( fission products ) ) ( ( ( are ( ( ( highly radioactive ) and ) ( most decay ) ) ) ( by ( ( Simultaneous emission ) ( of ( electrons ( and ( gamma rays ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (JJ Fresh) (NN fission) (NNS products)) (VP (VBP are) (ADJP (ADJP (RB highly) (JJ radioactive)) (CC and) (ADJP (RBS most) (JJ decay))) (PP (IN by) (NP (NP (NNP Simultaneous) (NNP emission)) (PP (IN of) (NP (NNS electrons) (CC and) (NN gamma) (NNS rays)))))) (. .)))
Fresh fission products are highly radioactive and most decay by Simultaneous emission of electrons and gamma rays.
(ROOT (S (PP (IN Of) (NP (NP (DT the) (CD three) (JJ basic) (NNS types)) (PP (IN of) (NP (JJ radioactive) (NNS emissions))))) (, ,) (NP (DT the) (NN gamma) (NN particle)) (VP (VBZ is) (NP (DT the) (JJS most) (NN penetrating))) (. .)))