( ( The transducer ) ( ( ( ( ( sends out ) ( ( sound waves ) ( that ( pass ( through ( the body ) ) ) ) ) ) and ) ( are ( echoed back ) ) ) . ) )
(ROOT (S (NP (DT The) (NN transducer)) (VP (VP (VBZ sends) (PRT (RP out)) (NP (NP (JJ sound) (NNS waves)) (SBAR (WHNP (WDT that)) (S (VP (VBP pass) (PP (IN through) (NP (DT the) (NN body)))))))) (CC and) (VP (VBP are) (VP (VBN echoed) (ADVP (RB back))))) (. .)))
The transducer sends out sound waves that pass through the body and are echoed back.
(ROOT (S (NP (DT A) (-LRB- -LRB-) (NN n) (-RRB- -RRB-)) (VP (VBP echo) (SBAR (S (VP (VBZ is) (VP (VBN heard) (SBAR (WHADVP (WRB when)) (S (NP (JJ sound) (NNS waves)) (VP (VBP bounce) (ADVP (RB back)) (PP (IN from) (NP (DT a) (NN surface))) (SBAR (IN that) (S (NP (PRP they)) (VP (MD ca) (RB n't) (VP (VB pass) (PRT (RP through)))))))))))))) (. .)))