( ( ( spin ( of ( black hole ) ) ) ( ( slows down ) ( ( Black holes ) ( found ( as ( member ( of ( binary ( star ( system ( Visible companion ) ) ) ) ) ) ) ) ) ) ) ( ( usually ( blue ( supergiant ( Visible ( companion transfers ) ) ) ) ) ( ( matter ( to ( unseen ( ( black ( hole companion ) ) ( Matter ( forms ( ( large ( accretion disk ) ) ( around ( black hole ) ) ) ) ) ) ) ) ) ; ) ) )
(ROOT (S (SBAR (S (NP (NP (NN spin)) (PP (IN of) (NP (JJ black) (NN hole)))) (VP (VBZ slows) (PRT (RP down)) (NP (NP (JJ Black) (NNS holes)) (VP (VBN found) (PP (IN as) (NP (NP (NN member)) (PP (IN of) (NP (JJ binary) (NN star) (NN system) (NN Visible) (NN companion)))))))))) (NP (RB usually) (JJ blue) (JJ supergiant) (NNP Visible) (NN companion) (NNS transfers)) (VP (VBP matter) (S (VP (TO to) (VP (VB unseen) (NP (NP (JJ black) (NN hole) (NN companion)) (SBAR (S (NP (NNP Matter)) (VP (VBZ forms) (NP (NP (JJ large) (NN accretion) (NN disk)) (PP (IN around) (NP (JJ black) (NN hole)))))))))))) (: ;)))
spin of black hole slows down Black holes found as member of binary star system Visible companion usually blue supergiant Visible companion transfers matter to unseen black hole companion Matter forms large accretion disk around black hole;
(ROOT (S (NP (NP (DT The) (JJ tidal) (NNS forces)) (PP (IN near) (NP (JJ black) (NNS holes)))) (VP (VBP are) (ADJP (RB so) (JJ great) (SBAR (S (NP (PRP they)) (VP (MD can) (ADVP (RB actually)) (VP (VB tear) (NP (NN matter)) (PP (IN from) (NP (DT a) (NN companion) (NN star))))))))) (. .)))