问题 单项选择题

动态主机配置协议 DHCP 是对BOOTP 协议的扩充,DHCP 与BOOTP 的主要区别是DHCP 具有(26)机制。DHCP 协议支持的中继代理(Relay Agent)是一种(27),它可以在不同的网段之间传送报文。DHCP 具有多种地址分配方案,对于移动终端(比如笔记本电脑)最适合的分配方案是(28) 。使用 Windows 2000 操作系统的 DHCP 客户机,如果启动时无法与DHCP 服务器通信,它将(29) 。因为 DHCP 报文是装入(30) 协议数据单元中传送的,所以它是不安全的。

27()

A.使用DHCP 协议的路由器

B. 转发DHCP 报文的主机或路由器

C.可访问到的DHCP 主机

D.专用的服务器

答案

参考答案:B

单项选择题 A1/A2型题
单项选择题

Until recently, most population growth has occurred in relatively dense urban environments. In (91) words, even if we were witnessing rapid population growth, that would not mean that the (92) were filling in with people. (93) , the urban areas would tend to become more crowded. Historically, we find that people have moved to (94) the jobs were. Jobs were usually in ports or locations with many natural (95) . After transportation became relatively cheap, other geographical locations became (96) of economic activity. One factor that determines where people will move to, even when transportation becomes cheap, is (97) . And individuals working in cities (98) higher incomes than those working in (99) areas. Hence, population has tended until the 1970s to (100) in our major urban centers. Recently population has (101) out of the Northeast to the South and to the West for the more pleasant climates. If people did not (102) from living in large cities, there would likely be a much more even population distribution (103) our entire land area. Probably, if this (104) the case, there would be less concern over population (105) Indeed, one need only (106) a cross-country drive or plane trip to realize how (107) populated these United States really are. This is not to say that we should or should not do something about (108) growth. The shortage of people in certain areas merely demonstrates that overpopulation in the United States is really only a problem in (109) urban environments. And this problem may be slowly correcting (110) .

A.enrich

B.increase

C.decrease

D.enlarge