Astute service providers realize that the continued support of legacy X.25 and asynchronous network element using separate operations network is cost（1）. 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（2）hence,additional maintenance procedures must be maintained and administrative records are（3）the duplication of trasport facilities to carry（4）network traffic is an inefficient use of resources and,not surprisingly,more technologies installed in a central office mean the necessity for more physical space,and an increase in power connections and power consumption.migration of these（5）network elements to IP-based DCns is alogical strategy

3（）

A.declined 

B.proliferated 

C.destroyed 

D.produced

日本的铁路运输十分准时，但是难免会遇到暴雨或台风。一旦遇到这样的突发问题，列车员都会给每一个旅客发一个证明，而人们拿着这个证明到单位就不会被扣工资。请结合实际工作谈谈你对此事的看法。