在电子商务中，保证数据传输的安全性就是______。A．保证在公共因特网上传送的数据

长江三峡大坝上下游水位差最高可达113 m，上游的船要在 船闸中经过5个闸室使船体逐渐降低，每个闸室水位变化二 十多米，因而三峡船闸的闸门非常大．其首级人字闸门每扇 高39.5m，宽20.2m．倘若门外的水位高30m，则这扇闸门所受水的最大压强是_________ Pa，已知闸门所受水的平均压强 是最大压强的一半，则这扇闸门所受水的压力是_________ N．(g取10N/kg)

（）说：“天地有大美而不言。”

A.荀子

B.韩非

C.苏轼

D.庄子

药材槲寄生的原植物科名是（）

A.小檗科

B.桑寄生科

C.列当科

D.兰科

E.豆科

astute service providers realize that the continued support of legacy X.25 and asynchronous network element using separate operations network is cost (141) . For example, the maintenance of multiple networks can require additional staff. Often, this staff must be trained on multiple vendor technologies, sometimes requiring parallel groups specializing in each (142) . Hence, additional maintenance procedures must be maintained and administrative records are (143) . The duplication of transport facilities to carry (144) network traffic is an inefficient use of resources. And not surprisingly, more technologies installed in a central office means the necessity for more physical space and an increase in power connections and power consumption, migration of these (145) network elements to IP-based DCns is alogical strategy.

A．declined

B．proliferated

C．destroyed

D．produced

ISDN是指（）

A.电话业务网

B.电视业务网

C.手机业务网

D.综合业务数字网