( ( ( Corals and ) ( ( the formation ) ( of coral ) ) ) ( reefs . ) )
(ROOT (S (NP (NP (NNS Corals)) (CC and) (NP (NP (DT the) (NN formation)) (PP (IN of) (NP (NN coral))))) (VP (VBZ reefs)) (. .)))
Corals and the formation of coral reefs.
(ROOT (S (NP (NNS Corals)) (VP (VBP build) (NP (NP (JJ hard) (NNS exoskeletons)) (SBAR (WHNP (WDT that)) (S (VP (VBP grow) (S (VP (TO to) (VP (VB become) (NP (NN coral) (NNS reefs)))))))))) (. .)))