( ( ( ( ( ( ( ( Interstellar dust ) , ) ( interstellar extinction ) ) , ) ( interstellar gas ) ) , ) nebulae ) ; )
(ROOT (NP (NP (JJ Interstellar) (NN dust)) (, ,) (NP (NN interstellar) (NN extinction)) (, ,) (NP (NN interstellar) (NN gas)) (, ,) (NP (NN nebulae)) (: ;)))
Interstellar dust, interstellar extinction, interstellar gas, nebulae;
(ROOT (S (NP (JJ Interstellar) (NN medium)) (VP (VBZ consists) (PP (IN of) (NP (NP (RB thinly) (NN spread) (NN gas)) (CC and) (NP (NN dust))))) (. .)))