7．It began as a game：high school and college students studying computer technology figured out they could use personal computers to break into telephone company computers and make free，long-distance telephone calls．These young computer wizards （奇才） soon gained the nickname"hackers （黑客）"．
Police put the collar on （拘留，逮捕） a few hackers，but many went on to even more complex hacking．One hacker was arrested for making illegal telephone calls and later used a prison phone to alter a police officer's credit records to get back at （報(bào)復(fù)） the officer for arresting him．The hacker also used a computer to alter his college records to give himself better grades．
As hackers gained experience，they began invading computers at banks，airlines and other businesses．In one scheme，a hacker instructed an airline's computer to give him free airplane tickets．
The U．S．government is worried hackers may break into its complex networks of defense computers．The government's classified secrets are weak because thousands of government computers are connected by telephone lines that hackers can tap into．
In November 1988，a college student tapped into a non-classified U．S．Defense Department computer network called Arpanet．The hacker injected （輸入，注入） a computer program that left copies of itself throughout Arpanet．Some hackers use each"viruses"to destroy all the data in a computer．But in this case，government officials shut down the network before the program reached every computer in the system．Shutting down the system angered many researchers who were using the computers．The hacker turned himself in （自首） to police and told them how to get his program out of the computer system．He was charged with a crime．
The incident put the focus on computer hacking in the United States．Many companies have hired experts to protect their computers from hackers，and many computer experts now advise companies on how to protect their computers．
The U．S．government believes foreign governments have hired hackers to try to break into top-secret defense computers．It fears a hacker could inject a virus into military computers that would erase all the data during a war．
Experts disagree over whether a computer network can ever be safe from hacking．But in the future，some of the most brilliant minds in the U．S．will be working to defeat the efforts of computer hackers and spies．
Choose the correct answer．
54．The main idea of the article isC．
A．computer hackers only want to make free long-distance phone calls
B．the government wants to hire computer hackers to spy on the Russians
C．computer hackers are a threat to private companies and government secrets
D．many companies have hired experts to protect their computers from hackers who carry viruses
55．A hacker can be dangerous becauseB．
A．he knows how to make free long-distance telephone calls
B．vital information is stored in computers，and a hacker knows how to change or erase the information
C．once in jail，he can use a telephone to operate his computer
D．a(chǎn) hacker who steals a free airplane ticket might cause a doctor to lose that seat on the airplane
56．U．S．government computers are vulnerable to a hacker becauseD．
A．the government always pays its telephone bills on time
B．the Russians know what's in the U．S．computers
C．viruses attack only government computers
D．many government computers are connected by telephone lines
57．In the futureA．
A．Some of the most brilliant minds in America will be working to try to stop computer hackers and spies
B．hackers will begin invading computers at banks，airlines and other businesses
C．many computer hackers will be arrested for making free telephone calls
D．some computer hackers will turn themselves in to the police．
分析 本文主要講述電腦黑客威脅私人公司和政府的秘密．
解答 CB DA
54 C 主旨大意題． 通讀全文可知本文主要講述電腦黑客威脅私人公司和政府的秘密．故選C．
55 B 細(xì)節(jié)題． 根據(jù)文章第二 段The hacker also used a computer to alter his college records to give himself better grades．可知黑客危險(xiǎn)的原因是重要的信息存儲在計(jì)算機(jī)，黑客知道如何更改或刪除信息，故選B．
56 D 細(xì)節(jié)題． 根據(jù)文章第四 段The government's classified secrets are weak because thousands of government computers are connected by telephone lines that hackers can tap into．可知政府電腦容易受到攻擊的原因是政府的電腦都是用電話線連接的，故選D．
57 A 細(xì)節(jié)題． 根據(jù)文章最后一 段 in the future，some of the most brilliant minds in the U．S．will be working to defeat the efforts of computer hackers and spies．可知在未來，美國的一些最聰明的頭腦將設(shè)法阻止電腦黑客和間諜工作，故選A．
點(diǎn)評 做閱讀理解時(shí)要快速的瀏覽全文，把握文章主旨大意，帶著問題回到原文，尋找細(xì)節(jié)或概括相應(yīng)的答案，最后要理清作者寫作思路．
