IP multicasting is a set of technologies that enable efficient delivery of data to manylocations on a network．Rather than making multiple copies of a message intended to bedistributed to multiple recipients at the (71) of origin of a message，multicasting initiallysends just one (72) and does not copy it to the individual recipients until it reaches theclosest common point on the network，thereby (73) the bandwidth consumed．Networkperformance is significantly (74) because it isn’t bogged down with the processing andtransmission of several large data files；each receiving computer doesn’t have to (75) thetransmitting server for the file．

A．dropped
B．proved
C．improved
D．upgraded

上海解放后，上海市军管会在进行私营报刊登记的同时，也对其他的报道内容做了原则规定（）

A.禁止利用国民党中央通讯社及帝国主义国家通讯社的电讯稿

B.发布军事消息一切有关政策及刊发中 * * 发布的一切文件著作及有关政府的消息时，必须全文爱用新华社的消息

C.不得解释中共及军政的法令政策

D.各报发布的社会消息必须遵守新民主义中国之新闻呢一般原则，实事求是崇尚科学向人民服务