竖向扩大模数采用的值有()
A、3M
B、6M
C、12M
D、15M
E、30M
参考答案:A, B
在-44,-43,-42,…,1995,1996这一串连续的整数中,前100个连续整数的和等于______.
In HDLC protocol , when supervisory frame's type code is '11'. About the following Statements, which is correct ( )
A.receive ready
B.receive not ready
C.reject
D.selective reject