长途数字电话网由DC1和DC2两级长途交换中心构成，DC1为省级交换中心，DC1之间以（15 ）相互连接，DC1与本省内各地市的DC2以（16）连接。[1分]

100（）[1分]

99（）[1分]

98（）[1分]

The approaching 4G mobile communication systems are projected to （ ） still remaining problems of 3G systems and to provide （ ） newservices ,from high-quality voice to high-definition video to high data-rate wireless channels.[1分]

Deploying enhanced broadband services over existing network infrastructure （ ）in increase of the network complexity and therefore,extraexpenses on network management and maintenanc

The approaching 4G mobile communication systems are projected to （ ） still remaining problems of 3G systems and to provide （ ） newservices ,from high-quality voice to high-definition video to high data-rate wireless channels.[1分]

4G is the fourth generation wireless technology adopted by the （ ） and carriers around the worl

Nobody had predicted the scale of impact of （ ） communications and that it world be one of the largest businesses in the history of mankind with and immense impact on all economies.[1分]

分布式数据库中的数据分布在不同节点上，有的事务分解成不同节点上的多个局部事务，若某个局部事务不能正常提交，则必须撤销所有其他节点已提交的局部事务。事务的这种性质，被称为事务的（ ）。[1分]

在通信专业中，WDM的英文全称是（ ），“吞吐量”英文通常翻译为（ ）。[1分]