Who do you think we should have _____ to Shanghai to visit the 2010 World Expo? [ ]

A. to go

B. gone

C. going

D. go

光缆障碍处理中应遵循“（）”的原则，不分白天黑夜、不分天气好坏、不分维护界限，用最快的方法临时抢通传输系统，然后再尽快恢复。