( ( ( Divide ( the class ) ) ( into ( seven groups ) ) ) . )
(ROOT (S (VP (VB Divide) (NP (DT the) (NN class)) (PP (IN into) (NP (CD seven) (NNS groups)))) (. .)))
Divide the class into seven groups.
(ROOT (S (NP (NNS Mollusks)) (VP (MD can) (VP (VB be) (VP (VBN divided) (PP (IN into) (NP (CD seven) (NNS classes)))))) (. .)))
Mollusks can be divided into seven classes.