帧中继网的虚电路建立在数据链路层，其用户平面采用(24)协议。

In　a　data　warehouse　environment,　data　is　only　valuable　when　it　is　organized　and　displayed　as(75)

Communication　networks　can　be　classified　in　terms　of　their　physical　arrangement　or(74)Three　common(74)are　the　star,　bus,　and　ting.

A　computer　network　links　computers　together　to　allow　users　to　share　hardware,　software,　and(73)

The　basic　concept　of　a　data(72)is　the　difference　between　data　and　information.

There　is　free　firewall　software　available　that　can　run　on　minimal　hardware　and　provide　a　good　level　of(71)to　your　network.

A　multimedia　system　allows　end　users　to　share,　transfer　and　process　a　variety　of　forms　of　information　in　a(70)manner.

A　small　network　may　only　connect　two　computers　inside　a　home　to　share　a　single　printer　and　Internet(69)

The　World　Wide　Web　is　the　latest　evolution　of　an　effort　to　make　information　on　computers(68)the　world　available　to　as　many　users　as　possible.

In　recent　years,　TCP/IP　has　also　begun　to　be　used　by　telephone　companies　to　provide　faster,　cheaper　telephone(67)

A　high-level　language　is　an　artificial　language　with　which　we　can　write　various(66)