ISDN基群接入PA的速率为（）。
A.1024kbit/s
B.2048kbit/s
C.4096kbit/s
D.8192kbit/s
参考答案：B
As is recorded in history, silkworms (蚕) were first raised by a woman in _________ is today Hebei Province.
A．where
B．the place
C．which
D．what
_______和_______是水痘的传播途径。
