C. error flag 答案:b 54.起始位 a. start bit b. stop bit c. parity bit 答案 空号电平 a. mark level b. space level c. the idle state 答案 56.控制比特 binary data b. local clock c. control bit 答案 57.串行接口 a. data stream b. Crt terminal c. serial interface 答案 58.发送器和接收器 a. transmitter and receiver b. receiver timing c. duration of t seconds 答案:a 59.二进制数据 答案: y data b. data stream c. data transmission a. bina 60.高速电子开关 a. the voice channel b. the repetition rate high-speed switch 答案:c II.根据所给英文选择合适的答案 1. digital communication a.全球通信b.公共通信载体c.数字通信 答案 2. voice encoding techniques a.语音编码技术b.脉冲c.脉冲编码调制 答案:a 3. basic access signaling rate a.大量的接口设备 b.基本接入信令速率 C.统一的接入 答案:b 4. the International Organization for Standardization a.综合业务数字网b.ISDN的标准和系统结构c.国际标准化组织 答案 5. end-to-end digital connectivity a.基本接入信令速率b.端对端的数字连接 C.语音编码技术 答案:b 6. progressive application of digital technologyc. error flag 答案：b 54. 起始位 a. start bit b. stop bit c. parity bit 答案：a 55.空号电平 a. mark level b. space level c. the idle state 答案：b 56.控制比特 a. binary data b. local clock c. control bit 答案：c 57.串行接口 a. data stream b. CRT terminal c. serial interface 答案：c 58.发送器和接收器 a. transmitter and receiver b. receiver timing c. duration of T seconds 答案：a 59.二进制数据 a. binary data b. data stream c. data transmission 答案：a 60.高速电子开关 a. the voice channel b. the repetition rate c. a high-speed switch 答案：c II.根据所给英文选择合适的答案 1． digital communication a.全球通信 b. 公共通信载体 c.数字通信 答案：c 2． voice encoding techniques a.语音编码技术 b. 脉冲 c. 脉冲编码调制 答案：a 3． basic access signaling rate a.大量的接口设备 b. 基本接入信令速率 c. 统一的接入 答案：b 4． the International Organization for Standardization a.综合业务数字网 b. ISDN 的标准和系统结构 c. 国际标准化组织 答案：c 5． end-to-end digital connectivity a. 基本接入信令速率 b.端对端的数字连接 c. 语音编码技术 答案：b 6． progressive application of digital technology