如下图所示,网桥 A、B、C 连接多个以太网。已知网桥 A 为根网桥,各个网桥的 a、b、 f 端口为指定端口。那么按照快速生成树协议标准 IEEE 802.1d-2004,网桥 B 的 c 端口为()。
A. 根端口(Root Port)
B. 指定端口(Designated Port)
C. 备份端口(Backup Port)
D. 替代端口(Alternate Port)
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在 Wmdows 的 DOS 窗口中键入命令 C:\> nslookup > set type=ptr >211.151.91.165 这个命令序列在 Wmdows 的 DOS 窗口中键入命令 C:\>nslookup > set type=ptr >211.151.91.165 这个命令序列的作用是()。
A. 查询 211.151.91.165 的邮件服务器信息
B. 查询 211.151.91.165 到域名的映射
C. 查询 211.15191.165 的资源记录类型
D. 显示 211.151.91.165 中各种可用的信息资源记录
大叶性肺炎的典型X线表现为:()
A. 肺纹理增强,透光度减低
B. 肺叶或肺段云雾状阴影
C. 炎症部位呈蜂窝状透亮区
D. 大叶不均匀性阴影
E. 肺叶或肺段密度增高一致性阴影
I do a lot of management training each year for the Circle K Company. Among the topics we discuss in our (31) is the keeping of quality employees (雇员). "What has (32) you to stay long enough to becom
16. A. had been used B. has been used C. used D. was used
17. A. many B. much C. any D. some
18. A. as well B. either C. too D. as well as
19. A. was born B. is born C. were born D. are born
20. A. when B. how C. which D. where