计算机网络最突出的特点是( )。 A．运算速度快 B．运算精度高 C．资源共享

我国诗歌史上雄视古今的“双子星座”的伟大诗人是谁？

2008年6月6日是第十三届全国爱眼日，主题是“明亮眼睛迎奥运”．

（1）眼球好象一架照相机，晶状体和角膜的共同作用相当于一个______透镜，视网膜上成的像是______像（填“实”或“虚”）．

（2）要科学用眼，注意用眼卫生，读书时，眼睛与书本的距离应保持______cm．

（3）矫正近视眼，要配戴近视眼镜，近视镜是______透镜．

竣工验收是国内投资项目在后评价之前最重要的环节，项目竣工验收的( )又是进行项目后评价的重要基础。

A．内容

B．文件

C．方法

D．程序

E．资料

Border Gateway Protocol(BGP) is inter-autonomous system (96) protocol. BGP is based on a routing method called path vector routing. Distance vector routing is not a good candidate for inter-autonomous system routing because there are occasions on which the route with the smallest (97) count is not the preferred route. For example, we may not want a packet through an not secure even though it is the shortest route. Also, distance vector routing is unstable due to the fact that the routers announce only the number of hop counts to the destination without actually defining the path that leads to that (98) . A router that receives a distance vector advertisement packet may be fooled if the shortest path is actually calculated through the receiving router itself. Link (99) routing is also not a good candidate for inter-autonomous system routing because an Internet is usually too big for this routing method. To use link state routing for the whole internet would require each router to have a huge link state database. It would also take a long time for each router to calculate its rousting (100) using the Dijkstra algorism.

（96）是（）

A.routing

B.switching

C.transmitting

D.receiving

1975年由泽文和茹可夫斯基共同编写的《栽培植物及其变异中心检索》确定的地理基因起源中心有（）个。

A.12

B.13

C.14

D.15