( ( Its ( major role ) ) ( ( is ( to ( ( ( assist ( the body ) ) ( in thermoregulation ) ) ( -LRB- ( ( maintaining ( normal ( body temperature ) ) ) -RRB- ) ) ) ) ) . ) )
(ROOT (S (NP (PRP$ Its) (JJ major) (NN role)) (VP (VBZ is) (S (VP (TO to) (VP (VB assist) (NP (DT the) (NN body)) (PP (IN in) (NP (NN thermoregulation))) (PRN (-LRB- -LRB-) (S (VP (VBG maintaining) (NP (JJ normal) (NN body) (NN temperature)))) (-RRB- -RRB-)))))) (. .)))
Its major role is to assist the body in thermoregulation (maintaining normal body temperature).
(ROOT (S (NP (NNP Thermoregulation)) (VP (VBZ is) (NP (NP (DT the) (NN process)) (SBAR (WHNP (WHADVP (WRB when)) (NNS animals)) (S (VP (VBP maintain) (NP (DT an) (JJ internal) (NN temperature))))))) (. .)))