( They ( ( ( are ( no more ) ) ( to ( be ( trusted ( than ( bubbles ( floating ( on water ) ) ) ) ) ) ) ) ; ) )
(ROOT (S (NP (PRP They)) (VP (VBP are) (ADVP (DT no) (RBR more)) (S (VP (TO to) (VP (VB be) (VP (VBN trusted) (PP (IN than) (NP (NP (NNS bubbles)) (VP (VBG floating) (PP (IN on) (NP (NN water))))))))))) (: ;)))
They are no more to be trusted than bubbles floating on water;
(ROOT (S (NP (NNP Gas) (NN bubble) (NNS holes)) (VP (VBZ helps) (NP (NP (JJ pumice) (NN float)) (PP (IN in) (NP (NN water))))) (. .)))