ADSL的传输距离为（）。
A.1km
B.2km
C.2.5km
D.3-5km
参考答案：D
Language acquisition is concerned with language development in humans. Generally speaking, it refers to children’s development of their f language.
互联网面临着IP地址短缺的问题，下列技术（）不是解决IP地址短缺方案。
A．IPv6
B．NAT
C．CIDR
D．DHCP
