Regarding DHCP (dynamic host configuration protocol), which two of the following choices below are true?（）

A . Addresses are permanently assigned so that the host uses the same address at all times. B . Addresses are assigned for a fixed period of time. At the end of the period, a new request for an address must be made, and another address is then assigned. C . Addresses are leased to hosts. A host will usually keep the same address by periodically contacting the DHCP server to renew the lease. D . Addresses are allocated after a negotiation between the server and the host to determine the length of the agreement.

A . Addresses are allocated after a negotiation between the server and the host to determine the length of the agreement. B . Addresses are permanently assigned so that the hosts uses the same address at all times. C . Addresses are assigned for a fixed period of time, at the end of the period, a new request for an address must be made. D . Addresses are leased to hosts, which periodically contact the DHCP server to renew the lease.

A . hreqave B . hreqt C . n，p D . ho_recognised_period

A . 虚无假设 B . 研究假设 C . 原假设 D . 都不是

A . 等于 B . 小于 C . 大于 D . 无关

A . 正确 B . 错误

A . A DHCP client uses a ping to detect address conflicts.(ARP) B . A DHCP server uses a gratuitous ARP to detect DHCP clients. C . A DHCP client uses a gratuitous ARP to detect a DHCP server. D . If an address conflict is detected, the address is removed from the pool and an administrator must resolve the conflict. E . If an address conflict is detected, the address removed from the pool for an amount of time configurable by the administrator. F . If an address conflict is detected, the address is removed from the pool and will not be reused until server is rebooted.

A . 除了子网中网关、路由器以外使用DHCP B . 除了子网中网关、路由器，任何服务器和客户机都可以使用DHCP C . NT服务器不能使用DHCP D . 只有客户机才能使用DHCP

A . VLAN membership of a user always remains the same even when he/she is moved to another  location. B . VLAN membership of a user always changes when he/she is moved to another location. C . Membership can be static or dynamic. D . Membership can be static only. E . None of the other alternatives apply.

A . Addresses are allocated after a negotiation between the server and the host to determine the length ofthe agreement. B . Addresses are assigned for a fixed period of time.At the end of period，a newquest for an address mustbe made ，and another address is then assigned. C . Addresses are leased to host.A host will usually keep the same address by periodicallycontacting theDHCP sever to renew the lease. D . Addresses are permanently assigned so that the host uses the same address at all times.

A . 由于本征VLAN不是默认VLAN，DTP将无法协商中继链路。 B . 除非相连的远程接口也配置为动态期望模式，否则该接口无法协商中继链路 C . 相连的设备会动态确定必须通过该链路传输多个VLAN的数据的时机并根据需要打开中继链路。 D . 如果使用switchport mode dynamic auto命令或switc hportmode trunk命令配置远程相连设备，则会形成中继链路

A．A.Better cell HO B．B.Emergency HO C．C.Low battery HO D．D.Power budget HO

A.蠕虫病毒 B.木马病毒 C.ARP病毒 D.震荡波病毒

轻钢龙骨纸面石膏板隔墙，当其表面为一般装修时，其水平变形标准应是下列何值()。 A.≤Ho/60 B.≤Ho/120 C.≤Ho/240 D.≤Ho/360

是 否

A、Motion about the longitudinal axis B、Motion about lateral axis C、Motion about the vertical axis