( ( Binary compounds ) ( ( are ( composed ( of ( two ( elements only ) ) ) ) ) . ) )
(ROOT (S (NP (JJ Binary) (NNS compounds)) (VP (VBP are) (VP (VBN composed) (PP (IN of) (NP (CD two) (NNS elements) (RB only))))) (. .)))
Binary compounds are composed of two elements only.
(ROOT (S (NP (DT A) (JJ binary) (JJ molecular) (NN compound)) (VP (VBZ is) (VP (VBN made) (PRT (RP up)) (PP (IN of) (NP (CD two) (NNS elements))))) (. .)))