( ( ( ( You ( have ( to ( know ( enough ( to ( know ( what ( ( the ( common elements ) ) are ) ) ) ) ) ) ) ) ) -- ) ( ( ( ( they ( ( 're usually ) ( public schools ) ) ) , ) and ) ( ( ( almost all ) ( of them ) ) ( are ( ( ( very small ) schools ) ( with ( ( very small ) ( class sizes ) ) ) ) ) ) ) ) . )
(ROOT (S (S (NP (PRP You)) (VP (VBP have) (S (VP (TO to) (VP (VB know) (ADJP (JJ enough) (S (VP (TO to) (VP (VB know) (SBAR (WHNP (WP what)) (S (NP (DT the) (JJ common) (NNS elements)) (VP (VBP are))))))))))))) (: --) (S (S (NP (PRP they)) (VP (VBP 're) (ADVP (RB usually)) (NP (JJ public) (NNS schools)))) (, ,) (CC and) (S (NP (NP (RB almost) (DT all)) (PP (IN of) (NP (PRP them)))) (VP (VBP are) (NP (NP (ADJP (RB very) (JJ small)) (NNS schools)) (PP (IN with) (NP (ADJP (RB very) (JJ small)) (NN class) (NNS sizes))))))) (. .)))
You have to know enough to know what the common elements are -- they're usually public schools, and almost all of them are very small schools with very small class sizes.
(ROOT (S (NP (DT All) (NNS cells)) (VP (VBP have) (NP (NP (DT the) (JJ small) (NN size)) (PP (IN in) (NP (JJ common))))) (. .)))