( ( The ( ( most ( biologically important ) ) types ) ) ( ( are ( ionic ( , ( covalent ( , ( and ( hydrogen bonds ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (ADJP (RBS most) (RB biologically) (JJ important)) (NNS types)) (VP (VBP are) (UCP (ADJP (JJ ionic)) (, ,) (ADJP (JJ covalent)) (, ,) (CC and) (NP (NN hydrogen) (NNS bonds)))) (. .)))
The most biologically important types are ionic, covalent, and hydrogen bonds.
(ROOT (S (NP (NN Hydrogen) (NN chloride)) (VP (VBZ is) (NP (DT a) (JJ covalent) (NN compound))) (. .)))