1. [单选题]●在数据通信过程中，将模拟信号还原为数字信号的过程称为(29) 。(29)
A. 调制
B. 解调
C. 流量控制
D. 差错控制
2. [单选题]is a one-way function that takes an arbitrarily long piece of plaintext and from it computes a fixed-length bit string.(67)is a protocol that most USENET machines how use it to allow news articles to propagate from one machine to another over a reliable connection.(68)is an approach preferred by cable TV providers. In this solution the fiber terminates at an optoelectrical converter and the final segment is a shared coaxial cable.(69)is a device used to connect two separate network that use different communication protocol.(70)js a digital
A. MD
B. RSA
C. DES
D. MIB
