问题 填空题

当信息从信源向信宿流动时可能会受到攻击。其中中断攻击是破坏系统资源,这是对网络 ______性的攻击。

答案

参考答案:可用性

解析: 中断是指系统资源遭到破坏或变得不能使用,这是对可用性的攻击例如,对一些硬件进行破坏、切断通信线路或禁用文件管理系统。

阅读理解

Maybe everyone likes dogs, and almost everyone likes to read stories about dogs.

  I have a friend. He has a large police dog named Jack. Police dogs are very clever. Every Sunday afternoon my friend takes Jack for a long walk in the park. Jack likes these long walks very much.

  One Sunday afternoon a young man came to visit my friend. He stayed a long time. He talked and talked. Soon it was time for my friend to take Jack for his walk. But the visitor still stayed. Jack became very worried. He walked around the room several times and then sat down in front of the visitor and looked at him. But the visitor paid no attention to Jack. He went on talking. At last Jack got angry. He went out of the room and came back a few minutes later. He sat down again in front of the visitor, but this time he took the visitor’s hat in his mouth. The visitor saw it and was surprised. He laughed and left.

小题1:--The young visitor stayed a long time, didn’t he?

  --_____.

A.Yes, he didn’t

B.No, he didn’t

C.Yes, he did

D.No, he did小题2:Jack became worried because _____.

A.he wanted to go out for a walk

B.he wanted to play with him

C.he didn’t know the young man

D.he wanted to eat something小题3:Jack sat down in front of the visitor because _____.

A.he wanted the visitor to talk to him

B.he wanted to talk with the young man

C.he wanted to show the visitor how clever he is

D.he wanted the visitor to leave小题4:The visitor went on talking and _____.

A.he paid no attention to his hat

B.he paid no attention to Jack

C.he didn’t know that his hat was taken away by Jack

D.he didn’t like Jack小题5:Jack went out of the room, but came back with _____ in his mouth.

A.food

B.nothing

C.something

D.the visitor’s hat

选择题