( ( The vertebrae ) ( ( are ( ( ( separated ( by ( ( tough ( , ( intervertebral disks ) ) ) ( of fibrocartilage ) ) ) ) and ) ( ( held together ) ( by ligaments ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN vertebrae)) (VP (VBP are) (VP (VP (VBN separated) (PP (IN by) (NP (NP (JJ tough) (, ,) (JJ intervertebral) (NNS disks)) (PP (IN of) (NP (NN fibrocartilage)))))) (CC and) (VP (VBN held) (ADVP (RB together)) (PP (IN by) (NP (NNS ligaments)))))) (. .)))
The vertebrae are separated by tough, intervertebral disks of fibrocartilage and held together by ligaments.
(ROOT (S (NP (JJ Intervertebral) (NNS discs)) (VP (VBP are) (VP (VBN made) (PP (IN of) (NP (NN fibrocartilage))))) (. .)))