A. Oh, I have never seen you. B. Yes, I am glad. C. Hello, John. Nice to meet you. D. How are you?
A. 基于电路 B. 基于分组 C. 基于数据报 D. 基于网关
A. ±150 B. ±200 C. ±300 D. ±400
A. 正确 B. 错误