( ( NONPOLAR ( COVALENT BONDS ) ) ( ( ( occur ( between ( two atoms ) ) ) ( that ( share ( electrons equally ) ) ) ) . ) )
(ROOT (S (NP (NNP NONPOLAR) (NNP COVALENT) (NNS BONDS)) (VP (VBP occur) (PP (IN between) (NP (CD two) (NNS atoms))) (SBAR (IN that) (S (NP (NN share)) (VP (VBZ electrons) (ADVP (RB equally)))))) (. .)))
NONPOLAR COVALENT BONDS occur between two atoms that share electrons equally.
(ROOT (S (SBAR (WHADVP (WRB When)) (S (NP (NNS electrons)) (VP (VBP are) (VP (VBN shared) (ADVP (RB equally)))))) (, ,) (NP (PRP it)) (VP (VBZ is) (VP (VBN called) (NP (NN nonpolar) (NNS bonds)))) (. .)))