问题
选择题
The police ____ the murderer everywhere when he suddenly appeared in a theatre.[ ]
A. is searching for
B. were searching for
C. are searching for
D. was searching for
答案
答案：B
搜题请搜索小程序“爱下问搜题”
The police ____ the murderer everywhere when he suddenly appeared in a theatre.[ ]
A. is searching for
B. were searching for
C. are searching for
D. was searching for
答案：B
[说明]
某单位通过路由器实现NAT转换，网络拓扑结构如下图所示。其中所有服务器和客户机都使用私网地址，FTP服务器可对外提供服务。
路由器NAT映射地址及对应域名如下表所示。
| 表 路由器NAT映射地址及对应域名表 | |||
| 服务器名称 | 内网地址 | 外网映射地址 | 域名 |
| FTP服务器 | 192.168.1.2 | 61.11.52.99 | ftp.test.com |
| DNS服务器 | 192.168.1.3 | 61.11.52.100 | |
若某客户机使用IE可以正常访问网站，而QQ软件不能联网，可能的原因是（）。
A．DNS服务器配置错误
B．QQ软件代理配置错误
C．客户端机器网络线路故障
D．客户端机器网卡故障