某信道的带宽为4MHz，假定无噪声并采用4电平的数字信号，试求该信道的最大数据传输率。(要求列出简要计算式)

A. on line education will take the place of the traditional one soon
B. there are only a few on line programs until now
C. one need not take part in the exam in order to receive a diploma by way of online education
D. one can not receive a degree certificate of New York University through distant learning

A. 先天性巨结肠症常合并其他畸形，以中枢神经系统畸形发生率最高
B. 临床主要变现为不排胎粪或排粪延迟
C. 肛门指检时常有大量粪便、气体呈"爆炸"样排出
D. X线钡剂灌肠显示典型的狭窄、扩张、移行段即可确诊
E. 手术治疗是先天性巨结肠症唯一的治疗方式