( ( With ( strong ( calcium ( carbonate exoskeletons ) ) ) ) ( , ( crustaceans ( ( have ( ( a ( ( very effective ) shield ) ) ( against ( ( ( some ( potential enemies ) ) , ) ( who ( ( ( would simply ) not ) ( be ( able ( to ( ( bite ( through ( such ( a ( hard skeleton ) ) ) ) ) ( to ( ( reach ( the ( soft flesh ) ) ) inside ) ) ) ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN With) (NP (JJ strong) (NN calcium) (NN carbonate) (NNS exoskeletons))) (, ,) (NP (NNS crustaceans)) (VP (VBP have) (NP (NP (DT a) (ADJP (RB very) (JJ effective)) (NN shield)) (PP (IN against) (NP (NP (DT some) (JJ potential) (NNS enemies)) (, ,) (SBAR (WHNP (WP who)) (S (VP (MD would) (ADVP (RB simply)) (RB not) (VP (VB be) (ADJP (JJ able) (S (VP (TO to) (VP (VB bite) (PP (IN through) (NP (PDT such) (DT a) (JJ hard) (NN skeleton))) (S (VP (TO to) (VP (VB reach) (NP (DT the) (JJ soft) (NN flesh)) (ADVP (RB inside))))))))))))))))) (. .)))
With strong calcium carbonate exoskeletons, crustaceans have a very effective shield against some potential enemies, who would simply not be able to bite through such a hard skeleton to reach the soft flesh inside.
(ROOT (S (NP (PRP You)) (VP (VBP call) (NP (NP (DT the) (JJ hard) (NN case)) (SBAR (WHNP (WDT that)) (S (VP (VBZ surrounds) (NP (NP (DT the) (JJ soft) (NNS parts)) (PP (IN of) (NP (NP (DT some) (NNS animals)) (NP (DT the) (NN exoskeleton)))))))))) (. .)))