【判断题】
光纤裸纤一般分为三层，其中包层的作用是降低光折射率，折射率差可以保证光主要限制在纤芯里进行传输
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ATM技术是一种面向连接的交换技术，其信息交换单元的大小为53bit
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异步传输模式（ATM）是一种面向连接的交换技术，它以信元为单位进行数据传输
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物理层的主要功能是利用物理传输介质为数据链路层提供物理连接，以便透明地传送“比特”流
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防火墙可以防止利用标准网络协议中的缺陷进行攻击
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因特网是世界上最大的网络，它是典型的广域网
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资源子网提供访问网络和处理数据的能力，由主机系统、终端控制器和终端组成
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TCP提供的可靠性是利用一种称为“重传肯定确认”的机制来实现的
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防火墙不能防止利用服务器系统漏洞所进行的攻击
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从逻辑功能上看，计算机网络是由一些网络节点和连接这些节点的通信链路组成的
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如果ping不通默认网关，说明IP地址信息中有关默认网关的设置是错误的
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Internet其实就是一台提供特定服务的计算机
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同轴电缆只能传送数字信号，模拟信号要用光纤才可以传输
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MODEM是对传输信号进行A/D和D/A转换的，是在模拟信道中传输数字信号时不可缺少的设备
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网络层的协议ARP实现物理地址转换为IP地址的功能
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使用自己的电脑上互联网，肯定不会泄露私人信息
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接入网不可以在同一个网络中同时实现语音、数据和图像三种业务
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计算机网络的三个主要组成部分是若干主机、一个通信子网、一组通信协议
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在一个城市范围内所建立的计算机通信网称为城域网
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新版电子银行自助签约账户转账单笔限额是___元，日累计限额是（ ）元。( )
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— How are you, Bob?___
A. How are you?
B. I'm fine. Thank you.
C. How do you do?
D. Nice to meet you.
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— Thanks for your help.___
A. My pleasure.
B. Never mind.
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— Hello, my name is Charles Green, but ___ .
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— ___, and how are you?
A. Don't mention it
B. Hm, not too bad
C. Thanks
D. Pretty fast
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— I'm sorry. I am late due to the heavy traffic___
A. Well, it's OK.
B. No, it's all right.
C. You are welcome.
D. You are wrong.
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— It's rather cold in here. Do you mind if I close the window?___
A. Yes, please.
B. No, please.
C. Sure, please.
D. I don't like it.
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___He teaches physics in a school.
A. What does your father do?
B. Who is your father?
C. What is your father doing?
D. Where is your father now?
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— Excuse me, how much is the jacket?___ It's 499 Yuan.
A. Oh, no. That's OK!
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— Could you help me with my physics, please？___
A. No, no way.
B. No, I couldn't
C. No, I can't.
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— Could I borrow your car for a few days?___
A. Yes, you may borrow.
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— Thank you for inviting me.___
A. I really had a happy time.
B. Oh, it's too late.
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— May I see your tickets, please?___
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— Congratulations! You won the first prize in today's speech contest.___
A. Yes, I beat the others.
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— Must I take a taxi? No, you___. You can take my car.
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— We are going to have a singing party tonight. Would you like to join us?___
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— Hey, Tom, what's up?___
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— Do you mind my smoking here?___
A. No, thanks.
B. Yes, I do.
C. Yes. I'd rather not.
D. Good idea.
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A. Who did that?
B. What's wrong with him?
C. How did that happen?
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— This box is too heavy for me to carry it upstairs.___
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A. Sure, here you are.
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— Excuse me, could you show me the way to the nearest post office?___ Oh yes! Two blocks away from here at the Green Avenue. You can’t miss it.
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— Wow! This is a marvelous room! I’ve never known you’re so artistic.____
A. Great, I am very art-conscious.
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— Unbelievable! I have failed the driving test again!___ This is not the end of the world.
A. Good luck.
B.
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Are you feeling better today, Jack?___
A. There must be something wrong.
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Thank you so much for your lovely gift.___
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Would you like something to drink? What about a cup of tea?___
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What's the problem with your bike?___
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Good morning, John. How are you doing?___
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How do you do?___
A. Fine, thank you.
B. How do you do?
C. Not too bad.
D. Very well.
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Good-bye for now.___
A. The same to you.
B. That's OK
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