( They ( ( have ( been ( ( studying reflections ) ( at ( ( ( two ( engineering structures ) ) , ) ( ( rock islands ) ( ( protecting ( ( a ( beach ( and ( residential community ) ) ) ) ( at ( ( ( ( ( Elmer , ) ( West Sussex ) ) , ) and ) ( a ( berm breakwater ) ) ) ) ) ) ( at ( Plymouth Harbor ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP They)) (VP (VBP have) (VP (VBN been) (VP (VBG studying) (NP (NNS reflections)) (PP (IN at) (NP (NP (CD two) (NN engineering) (NNS structures)) (, ,) (NP (NP (NN rock) (NNS islands)) (VP (VBG protecting) (NP (NP (DT a) (NN beach) (CC and) (JJ residential) (NN community)) (PP (IN at) (NP (NP (NNP Elmer)) (, ,) (NP (NNP West) (NNP Sussex)) (, ,) (CC and) (NP (DT a) (NN berm) (NN breakwater))))) (PP (IN at) (NP (NNP Plymouth) (NNP Harbor)))))))))) (. .)))
They have been studying reflections at two engineering structures, rock islands protecting a beach and residential community at Elmer, West Sussex, and a berm breakwater at Plymouth Harbor.
(ROOT (S (NP (NP (NNS Structures)) (SBAR (WHNP (WDT that)) (S (VP (VB protect) (NP (DT the) (NN coast)) (PP (IN like) (NP (NN barrier) (NNS islands))))))) (VP (VBP are) (VP (VBN called) (NP (NNS breakwaters)))) (. .)))