《计算机专业英语》第 13 章在线测试

剩余时间：59:53

答题须知：1、本卷满分 20 分。 2、答完题后，请一定要单击下面的“交卷”按钮交卷，否则无法记录本试卷的成绩。 3、在交卷之前，不要刷新本网页，否则你的答题结果将会被清空。 第一题、单项选择题(每题 1 分，5 道题共 5 分) 1、Confidentiality of the message is not enough in a secure communication; ________ is also needed. The receiver ne eds to be sure of the sender’s identity. A、encryption C、authentication B、authorization D、encapsulation

2、The data, when they are not encrypted, are called ________. A、plaintext C、hypertext 3、A virus is a _________ . A、beast C、bad man 4、Many viruses go resident in the memory like a ( ). A、.exe file C、tsr program B、.com file D、data file B、computer D、program B、ciphertext D、context

5、Now, about ( ) different viruses account for all the viruses that actually spread in the wild. A、30 C、1800 第二题、多项选择题(每题 2 分，5 道题共 10 分) 1、Viruses all have two phases to their e xecution, the ( ) and the ( ). A、infection phase B、del_ete phase C、attack phase B、150 D、3000

D、creaｔe phase

2、( ) maybe a certain cause that some viruses infect upon.

A、a day B、a time

C、an external event on your PC D、a counter within the virus

3、Many viruses do harmful things such as ( ).

A、deleting files B、simulating typos C、slowing your PC down

D、changing random data on your disk

4、If a virus simply reproduce and have no cause for an attack phase, but it will still ( ) without your permission.

A、stealing storage B、pilfer CPU cycles C、del＿ete files D、play music

5、Some viruses, with no attack phase, often damage the programs or disks they infect because they ( ).

A、have bugs in them

B、contain poor quality code C、steal storage

D、show messages on your screen

第三题、判断题（每题1分，5道题共5分）

1、Computer security is a branch of technology known as information security as applied to computers.

正确

错误

2、Michelangelo is a file sector.