whAt is thE mAin iDEA oF thE pAssAgE
A．mAss mEDiA is thE only mEAns to inFluEnCE thE soCiAl liFE.
B．mAss mEDiA toDAy is too muCh DominAtED By CommErCiAl intErEsts.
C．A puBliC poliCy is nEEDED to rEgulAtE thE mAss mEDiA.
D．DEmoCrAtiC liFE is DEtErminED By mAss mEDiA.