1. [单选题]IPv6 is currently in growing deployment around the world,() Internet address registries (RIRs) began to urge all resource managers to plan rapid adoption and conversion.
A. from
B. since
C. for
D. over
2. [多选题]电信网构成的基本要素主要有（）。
A. 用户终端设备(customer terminal equipment)
B. 网络节点
C. 传输链路
D. 用户环路
3. [单选题]移动通信的告诉发展直接反映了通信技术发展的()趋势。
A. 数字化
B. 智能化
C. 标准化
D. 个人化
