( ( ( ( ( ( ( ( ( ( HCl and ) ( PH 3 ) ) ( contain ( ( hydrogen ( but not ) ) ( a ( small ( electronegative atom ) ) ) ) ) ) , ) and ) ( ( dimethyl ether ) ( contains ( both ( ( hydrogen and ) oxygen ) ) ) ) ) , ) but ) ( ( the two ) ( ( are not ) bonded ) ) ) . )
(ROOT (S (S (S (NP (NP (NNP HCl)) (CC and) (NP (NNP PH) (CD 3))) (VP (VBP contain) (NP (NP (NN hydrogen)) (CONJP (CC but) (RB not)) (NP (DT a) (JJ small) (NN electronegative) (NN atom))))) (, ,) (CC and) (S (NP (JJ dimethyl) (NN ether)) (VP (VBZ contains) (NP (DT both) (NN hydrogen) (CC and) (NN oxygen))))) (, ,) (CC but) (S (NP (DT the) (CD two)) (VP (VBP are) (RB not) (ADJP (JJ bonded)))) (. .)))
HCl and PH 3 contain hydrogen but not a small electronegative atom, and dimethyl ether contains both hydrogen and oxygen, but the  two are not bonded.
(ROOT (S (NP (DT An) (NN ether)) (VP (VBZ is) (NP (NP (DT an) (JJ organic) (NN compound)) (SBAR (WHPP (IN in) (WHNP (WDT which))) (S (NP (CD two) (NN hydrocarbon) (NNS groups)) (VP (VBP are) (VP (VBG bonded) (PP (TO to) (NP (DT the) (JJ same) (NN oxygen) (NN atom))))))))) (. .)))