( However ( , ( ( IM magnets ) ( ( ( have ( excellent resistance ) ) ( to ( ( demagnetization ( and ( good retention ) ) ) ( of magnetism ) ) ) ) . ) ) ) )
(ROOT (S (ADVP (RB However)) (, ,) (NP (NNP IM) (NNS magnets)) (VP (VBP have) (NP (JJ excellent) (NN resistance)) (PP (TO to) (NP (NP (NN demagnetization) (CC and) (JJ good) (NN retention)) (PP (IN of) (NP (NN magnetism)))))) (. .)))
However, IM magnets have excellent resistance to demagnetization and good retention of magnetism.
(ROOT (S (NP (NNP Demagnetization)) (VP (VBZ is) (NP (NP (DT the) (NN process)) (SBAR (WHPP (IN in) (WHNP (WDT which))) (S (NP (DT a) (NN magnet)) (VP (VBZ loses) (NP (PRP$ its) (JJ magnetic) (NNS properties))))))) (. .)))