问题 多项选择题

DHCP报文有很多种类型,关于DHCP报文的封装的描述正确的()。

A.DHCP报文中包含Relay Agent IP Address字段,表示DHCP Relay的IP地址,如果到达DHCP服务器前经过了不止一个DHCP Relay,那么后续的DHCP Relay中继也会改变此字段

B.DHCP报文中Hops字段表示的是DHCP报文经过的DHCP Relay的数目,每经过一个DHCP Relay时,该字段加1

C.Options字段表示DHCP的选项字段,至少为512字节

D.DHCP通过Options字段包含了服务器分配给终端的配置信息,如网关IP地址,DNS服务器的IP地址,客户端可以使用IP地址的有效租期等信息

答案

参考答案:B, D

完形填空

根据短文内容,从短文后的选项中选出能填入空白处的最佳选项。该项中有两项为多余选项。

My mother is a diligent and kind woman. She is very busy from morning till night. As a teacher, she works hard.  ___小题1:___ Both my brother and I love her dearly as she loves us.

My mother has been teaching math at a middle school in my hometown. She goes to work early in the morning and does not return home until late in the afternoon. ___小题2:___She treats them with patience and teaches them well. For her excellent quality and very good teaching results, she has been elected as a model teacher several times.

___小题3:___ Every day, when she comes back home from work, she sets about doing housework, sweeping the living room and bedrooms or cleaning the furniture, and putting everything in good order. She seems to be busy all the time. As she has been very busy working every day, she looks older than her age. But she looks as cheerful and happy as ever. Mother never buys expensive dresses for herself, but she often buys some inexpensive but high quality clothes for us. ___小题4:___ She just eats a plain meal outside when she is too busy to cook herself. She lives a busy yet simple life, without any complaints.

Often she says to us, “Work while you work, and play while you play. That is the way to be happy and gay. If you do not work, you will become lazy and be of no use to society”. What a piece of good advice this is! ___小题5:___ This advice of hers will always serve as a guide to my behavior. My mother is great indeed, and I always feel proud of her.

A. As a mother, she takes good care of us and gives us every comfort.

B. She enjoys listening to classic music.

C Can you tell us something about your mother?

D. She loves her students and cares for them.

E. She never goes to expensive restaurants to enjoy meals.

F. My mother is hard-working and never wastes money.

G. I never forget it and always bear it in my mind.

名词解释