( Next ( , ( ( the class ) ( ( is ( divided ( into ( groups ( of ( ( ( three to ) seven ) students ) ) ) ) ) ) . ) ) ) )
(ROOT (S (ADVP (RB Next)) (, ,) (NP (DT the) (NN class)) (VP (VBZ is) (VP (VBN divided) (PP (IN into) (NP (NP (NNS groups)) (PP (IN of) (NP (QP (CD three) (TO to) (CD seven)) (NNS students))))))) (. .)))
Next, the class is divided into groups of three to seven students.
(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.