People tend to think of computers as isolated machines, working away all by themselves. So

People tend to think of puters as isolated machines, working away all by themselves. Some personal puters do without an outside link, like someone's secret cabin in the woods. But just as most of homes are tied to a munity by streets, bus routes and electric lines, puters that exchange intelligence are part of a munity local, national and even global network joined by telephone connections.
　　The puter network is a creation of the electric age, but it is based on old-fashioned trust. It cannot work without trust. A rogue (流氓) loose in a puter system called hacker is worse than a thief entering your house. He could go through anyone's electronic mail or add to, change or delete anything in the information stored in the puter's memory. He could even take control of the entire system by inserting his own instructions in the software that runs it. He could shut the puter down whenever he wished, and no one could stop him. Then he could program the puter to erase any sign of his ever having been there.
Hacking, our electronic-age term for puter break-in is more and more in the news, intelligent kids vandalizing（破坏）university records, even pranking (恶作剧) about in supposedly safeguarded systems. To those who understand how puter networks are increasingly regulating life in the late 20th century, these are not laughing matters. A potential for disaster is building: A dissatisfied former insurance-pany employee wipes out information from some files; A student sends out a virus, a secret and destructive mand, over a national network. The virus copies itself at lightning speed, jamming the entire network thousands of academic, mercial and government puter systems. Such disastrous cases have already occurred. Now exists the possibility of terrorism by puter. Destroging a system responsible for air-traffic control at a busy airport, or knocking out the telephones of a major city, is a relatively easy way to spread panic. Yet neither business nor government has done enough to strengthen its defenses against attack. For one thing, such defenses are expensive; for another, they may interrupt munication, the main reason for using puters in the first place.
59. People usually regard puters as      .
A. a small cabin at the end of a street  
B. part of a network
C. means of exchanging intelligence
D. personal machines disconnected from outside
60. The writer mentions “ a thief ”in the second paragraph most probably to      .
A. look into the case where hackers and thieves are the same people 
B. demand that a puter network should be set up against thieves
C. tell people that thieves like to steal puters nowadays
D. show that a hacker is more dangerous than a thief
61. According to the passage , a hacker may do all the damages below EXCEPT     .
A. destroying puter systems . 
B. creating many electronic-age terms .
C.. entering into puter systems without being discovered
D. attacking people’s e-mails
62. By saying “ Now exists the possibility of terrorism by puter ”(the underlined ) the writer means that     .
A. students who send out a “ virus ”may do disastrous damages to thousands of puters
B. some people may spread fear in public by destroying puter systems
C. some employees may erase information from some files
D. some terrorists are trying to contact each other using electronic mails DDBB