下列关于宽带城域网技术的描述中,错误的是
A. 能够为用户提供带宽保证,实现流量工程
B. 可以利用NAT技术解决IP地址资源不足的问题
C. 可以利用SNMP实现网络管理
D. 保证QoS的主要技术有RSVP、DiffServ、MSTP
Tigers and bears are very dangerous. That's () they have to stay in cages in the zoo.
A. why
B. where
C. how
D. what
Masson Fontana黑色素银浸染色的正确结果是
A. 黑色素呈黑色
B. 黑色素呈暗绿色
C. 嗜银细胞颗粒呈棕色D.细胞核呈蓝色
D. 胶原纤维呈紫色
If only I ()how to operate a computer as you do.
A. had known
B. would know
C. should know
D. knew