问题 单项选择题

使用Sniffer软件在网络设备的一个端口上能够捕捉到与之属于同一VLAN的不同端口的所有通信流量,这种网络设备是______。

A.Cable MODEM
B.路由器
C.交换机
D.集线器

答案

参考答案:C

解析: 虚拟局域网(VLAN)技术是以交换式网络为基础,能够把网络上用户的终端设备划分为若干个逻辑工作组。每个VLAN都是一个独立的逻辑网段、单一的广播域。通常,在二层交换机、三层交换机上进行与VLAN创建、端口分配等相关的配置工作。如果将具有Sniffer嗅探功能的设备连接在二层交换机的某个端口n上,则能够捕捉到与端口n归属于同一VLAN的不同端口(可以是一个,也可以是多个)的所有通信流量。同理,如果在三层交换机上将同一VLAN的不同端口进行镜像端口、被镜像端口的相关配置,那么也能完成这一功能。

单项选择题
阅读理解

Compassion(同情)is a desire within us to help others.With efforts,we can translate compassion into actions.An experience last weekend showed me this is true.

I work part—time in a supermarket across from a building for the elderly These old people are our main customers,and it’s easy to lose patience over their slowness.But last Sunday,one aged gentleman appeared to teach me a valuable lesson.This untidy marl walked up to my register(收款机)with a box of biscuits.He said he was out of cash,had just moved into his room,and had nothing in his cupboards.He asked if we could let him have the food on trust.He promised to repay me the next day.

I couldn’t help staring at him.I wondered what kind of person he had been ten or twenty years before,and what he would be like if luck had gone his way.I had a hurt in my heart for this kind of human soul,all alone in the world.I told him that I was sorry,and the store rules didn’t allow me to do so.I felt stupid and unkind saying this,but I valued my job .Just then,another man,standing behind the first,spoke up.if anything,he looked more pitiable,“Charge it to me,”was all he said.

What I had been feeling was pity.Pity is soft,safe and easy.Compassion,on the other hand,is caring in action.I thanked the second man but told him that was not allowed,either.Then I reached into my pocket and paid for the biscuits myself I reached into my pocket because these two men had reached into my heart and taught me compassion.

64.The aged gentleman who wanted to buy the biscuits           .

A.promised to obey the store rules

B.forgot to take any money with him

C.hoped to have the food first and pay later

D.couldn’t afford anything more expensive

65.How did the aged gentleman possibly feel when he was refused by the writer?

A.Warm and lucky.       B.shameful and lonely

C.Thankful and excited   D.Hurt and disappointed.

66.The writer followed the store rules because       .

A.he wanted to keep his present job

B.he felt no pity for the old gentleman

C.he considered the old gentleman dishonest

D.he expected someone else to pay for the old gentleman

67.What does the writer 1earn from his experience?

A.Wealth is most important.

B.Helping others is easier said than done.

C.Experience is better gained through practice.

D.Compassion shows in actions