[单选,共用题干题]

When the system upon which a transport entity is running fails and subsequently restarts,the(21) information of all active connections is lost. The affected connections become half-open, as the side that did not fail does not yet realize the problem.The still active side of a half-open connections can close the connection using a(22)timer. This timer measures the time the transport machine will continue to await an (23) of a transmitted segment after the segment has been retransmitted the maximum number of times.When the timer (24),the transport entity assumes that either the other transport entity or the intervening network has failed. As a result, the timer closes the connection, and signals an abnormal close to the TS user. In the event that a transport entity fails and quickly restarts, half-open connections can be terminated more quickly by the use of the RST segment, the failed side returns an RST i to every segment i that it receives. When the RST i reaches the other side, it must be checked for validity based on the (25) number i, as the RST could be in response to an old segment. If the reset is valid, the transport entity performs an abnormal termination.

空白处（25）应选择（）

阅读以下关于网络系统数据备份方面的叙述，回答问题1至问题3。 博学教育集团总公司的信息管理部门决定为信息中心的计算机网络制订一个相对完善的网络系统数据备份的整体解决方案。经讨论与分析后，普遍认为在该数据备份方案中必须实施以下要点： （1）选用专业级的网络备份管理软件，以代替原来使用的普通备份软件或者由网络操作系统中所提供的备份软件。 （2）选用可靠的存储介质，以优质磁带为主，辅以少量可记录光盘和若干可卸式硬盘或软盘片。 （3）选用性能价格比良好的自动加载磁带机，作为网络系统数据备份的主要备份设备。 （4）制定合理的备份策略。可能选用的备份策略允许包括完全备份方式、增量备份方式和差分备份方式，以及这些方式的组合。例如，完全备份方式可以是每天对网络系统进行全部数据的完全备份。增量备份方式可以是只在每周五进行一次完全备份，在以下的周一到周四只对当天新的或被改动过的数据内容进行备份。差分备份方式可以在每周五进行一次完全备份，在以下的周一至周四，每天对当天与上周五相比有不同的数据（新的或被改动过的）进行备份。 （5）建立起备份磁带和有关存储介质的严格管理制度，并由专人审计与监督备份的执行情况。 阅读以下关于电子政务系统安全体系结构的叙述，回答问题1～问题3。 博学公司通过投标，承担了某省级城市的电子政务系统，由于经费、政务应用成熟度、使用人员观念等多方面的原因，该系统计划采用分阶段实施的策略来建设，最先建设急需和重要的部分。在安全建设方面，先投入一部分资金保障关键部门和关键信息的安全，之后在总结经验教训的基础上分两年逐步完善系统。因此，初步考虑使用防火墙、入侵检测、病毒扫描、安全扫描、日志审计、网页防篡改、私自拨号检测、PKI技术和服务等保障电子政务的安全。 由于该电子政务系统涉及政府安全问题，为了从整个体系结构上设计好该系统的安全体系，博学公司首席架构师张博士召集了项目组人员多次讨论。在一次关于安全的方案讨论会上，谢工认为由于政务网对安全性要求比较高，因此要建设防火墙、入侵检测、病毒扫描、安全扫描、日志审计、网页防篡改、私自拨号检测系统，这样就可以全面保护电子政务系统的安全。王工则认为谢工的方案不够全面，还应该在谢工提出的方案的基础上，使用PKI技术，进行认证、机密性、完整性和抗抵赖性保护。 在Word中，利用（1）功能按钮，可以在画好的图形内填充颜色；在单击"绘图"工具栏上的"椭圆"按钮后，再按住（2）键进行绘制可确保绘出一个圆形。空白（2）处应选择（） Shift。 Ctrl。 Alt。 Tab。 When the system upon which a transport entity is running fails and subsequently restarts,the(21) information of all active connections is lost. The affected connections become half-open, as the side that did not fail does not yet realize the problem.The still active side of a half-open connections can close the connection using a(22)timer. This timer measures the time the transport machine will continue to await an (23) of a transmitted segment after the segment has been retransmitted the maximum number of times.When the timer (24),the transport entity assumes that either the other transport entity or the intervening network has failed. As a result, the timer closes the connection, and signals an abnormal close to the TS user. In the event that a transport entity fails and quickly restarts, half-open connections can be terminated more quickly by the use of the RST segment, the failed side returns an RST i to every segment i that it receives. When the RST i reaches the other side, it must be checked for validity based on the (25) number i, as the RST could be in response to an old segment. If the reset is valid, the transport entity performs an abnormal termination.空白处（23）应选择（） A.reset。 acknowledgment。 sequence。 synchroizer。 学生成绩表如下表所示。若要计算学生各科成绩、总分和平均分各项的最高分，可先在C10单元格中输入（1），并（2）拖动填充柄至H10单元格，则可自动算出这些学生各科成绩、总分和平均分的最高分。 空白（2）处应选择（） 向垂直方向。 向水平方向。 按住Shift键向垂直方向。 按住Shift键向水平方向。

When the system upon which a transport entity is running fails and subsequently restarts,the(21) information of all active connections is lost. The affected connections become half-open, as the side that did not fail does not yet realize the problem.The still active side of a half-open connections can close the connection using a(22)timer. This timer measures the time the transport machine will continue to await an (23) of a transmitted segment after the segment has been retransmitted the maximum number of times.When the timer (24),the transport entity assumes that either the other transport entity or the intervening network has failed. As a result, the timer closes the connection, and signals an abnormal close to the TS user. In the event that a transport entity fails and quickly restarts, half-open connections can be terminated more quickly by the use of the RST segment, the failed side returns an RST i to every segment i that it receives. When the RST i reaches the other side, it must be checked for validity based on the (25) number i, as the RST could be in response to an old segment. If the reset is valid, the transport entity performs an abnormal termination.

空白处（25）应选择（）