( ( The tadpoles ) ( ( ( ( feed ( on ( aquatic plants ) ) ) and ) ( ( ( grow quickly ) eventually ) ( ( developing ( ( limbs and ) lungs ) ) ( as ( they ( ( ( emerge out ) ( of ( their pools ) ) ) ( as ( tiny frogs ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NNS tadpoles)) (VP (VP (VB feed) (PP (IN on) (NP (JJ aquatic) (NNS plants)))) (CC and) (VP (VB grow) (ADVP (RB quickly)) (ADVP (RB eventually)) (S (VP (VBG developing) (NP (NNS limbs) (CC and) (NNS lungs)) (SBAR (IN as) (S (NP (PRP they)) (VP (VB emerge) (PRT (RP out)) (PP (IN of) (NP (PRP$ their) (NNS pools))) (PP (IN as) (NP (JJ tiny) (NNS frogs)))))))))) (. .)))
The tadpoles feed on aquatic plants and grow quickly eventually developing limbs  and lungs as they emerge out of their pools as tiny frogs.
(ROOT (S (NP (DT A) (NN frog)) (VP (VBZ develops) (NP (PRN (-LRB- -LRB-) (NP (NN a/an)) (-RRB- -RRB-)) (NNS lungs)) (SBAR (IN as) (S (NP (PRP it)) (VP (VBZ changes) (PP (IN from) (NP (DT a) (NN tadpole))) (PP (TO to) (NP (DT an) (JJ adult) (NN frog))))))) (. .)))