( Superconductors ( ( are ( materials ( which ( ( -LRB- ( ( under ( certain ( specific conditions ) ) ) -RRB- ) ) ( ( ( ( have ( zero resistivity ) ) , ) and ) ( are ( perfect diamagnets ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNS Superconductors)) (VP (VBP are) (NP (NP (NNS materials)) (SBAR (WHNP (WDT which)) (S (PRN (-LRB- -LRB-) (PP (IN under) (NP (JJ certain) (JJ specific) (NNS conditions))) (-RRB- -RRB-)) (VP (VP (VBP have) (NP (CD zero) (NN resistivity))) (, ,) (CC and) (VP (VBP are) (NP (JJ perfect) (NNS diamagnets)))))))) (. .)))
Superconductors are materials which (under certain specific conditions) have zero resistivity, and are perfect diamagnets.
(ROOT (S (NP (NNS Superconductors)) (VP (VBP are) (NP (NP (NNS materials)) (PP (IN with) (NP (NP (DT a) (NN resistivity)) (PP (IN of) (NP (CD zero))))))) (. .)))