ACCorDing to thE proFEssor, whiCh oF thE Following is not truE ABoutCBs
A、CBs, onE oF thE thrEEABC, nBC, AnDCBs) mAjor CommErCiAl nEtworks, wAs orgAnizED in 1928.
B、ColumBiABroADCAsting systEm BECAmE thE lArgEst rADio nEtwork in thE unitED stAtEs.
CBs BEgAn ExpErimEntAl tElEvision BroADCAsting in nEw york on july 13, 1946.
D．CBs BEgAn rEgulAr BlACk-AnD-whitE wEEkly BroADCAsts ovEr its wCBw-tv stAtion in nEw york.