Recently, several thousand computers in the United States were attacked by a virus. The co
The virus told each computer to make many copies of itself. Within a few minutes, all the computers' power was being used to make copies of the virus. The computer could do no other work. It finally slowed down greatly, or simply stopped working. Computer experts spent many days trying to destroy the virus in the computer system.
The experts agree the virus could have been much worse. They say it could have sent orders to destroy huge amounts of electronic information.
Many experts believe, the recent computer virus showed the need for better computer security (安全). But that is a problem. The affected system provides a free exchange (交换) of ideas and information among universities, private companies and government offices. Increasing security too much would destroy this exchange. It would slow progress on many important research projects.
Which of the following statements is true?
A.Many computers were attacked by a virus in the U. S.
B.Many computers attacked by a virus in the U.S. lost their information.
C.A computer virus can harm human body.
D.A computer virus can help the computer owner do many things.