A、in thE us, thE puBliC sChools ArE not totAlly FrEE.
B．Compulsory EDuCAtion in thE us inCluDEs 9 yEArs oF FrEE EDuCAtion.
C、stuDEnts mustn’t lEAvE sChool until thEy FinishED grADE 12 or rEACh thE AgE oF 16.
D．Books ArE proviDED to stuDEnts FrEE oF ChArgE without BEing rEturnED、