, sticking its head up for a breath of fresh air now and then . 
(ROOT (S (, ,) (VP (VBG sticking) (NP (PRP$ its) (NN head)) (PRT (RP up)) (PP (IN for) (NP (NP (DT a) (NN breath)) (PP (IN of) (NP (JJ fresh) (NN air))))) (ADVP (RB now) (CC and) (RB then))) (. .)))
(ROOT (S (, ) (VP (VBG ) (NP (PRP$ ) (NN )) (PRT (RP )) (PP (IN ) (NP (NP (DT ) (NN )) (PP (IN ) (NP (JJ ) (NN ))))) (ADVP (RB ) (CC ) (RB ))) (. )))