( ( Gas ( and ( silicone bubbles ) ) ) ( ( float ( in ( aqueous humor ) ) ) ; ) )
(ROOT (S (NP (NNP Gas) (CC and) (NN silicone) (NNS bubbles)) (VP (VBP float) (PP (IN in) (NP (JJ aqueous) (NN humor)))) (: ;)))
Gas and silicone bubbles float in aqueous humor;
(ROOT (S (NP (NNP Gas) (NN bubble) (NNS holes)) (VP (VBZ helps) (NP (NP (JJ pumice) (NN float)) (PP (IN in) (NP (NN water))))) (. .)))