On October 12, 1987, some Chinese scientists were working at the computers to look for information they needed. Suddenly they saw a lot of very bright spots(点 )crossing the computers’ screens. At the same time the computers were working much slower. To find out what was happening they stopped their work to check some parts of the computers. To their horror(恐惧), they found out that most of their stored information was got rid of( 除掉) by computer viruses! Obviously all these computers had been infected（感染 ） by computer viruses.

It is said that the computer viruses were made by a group of young man fond of playing tricks. They all had excellent education. They created the viruses just to show their intelligence.（才智）These kinds of computer viruses are named Jerusalem( 耶路撒冷 )Viruses. These viruses can stay in computers for a long time. When the time comes they will attack the computers by lowering the function(功能), damaging their normal programs or even getting rid of all the information.

We now come to know that Jerusalem Viruses often attack computers on Fridays and that they are spreading(传播) to a list of computers. Among the countries that suffering computer viruses are Britain, Australia, Switzerland and the U.S. But till now, how to get rid of the terrible remains a problem.

小题1:The group of young men created the viruses to __________. 

A．damage the computers

B．test their ability

C．play a trick on operators of the computers

D．tell the world that they were intelligent小题2:According to the passage, computer viruses seem to _______.

A．have been in nature for years

B．be difficult to get rid of at present

C．exist（存在） in any computers

D．be able to be got rid of in the near future小题3:The most serious damage caused by the viruses is that _______.

A．all the information stored in the computers is gone

B．the computer’s functions are lowered

C．the normal programs are damaged

D．the computers infected by the viruses can no longer be used小题4:According to the passage, which of the following is true?

A．Four countries found their computers were infected by viruses.

B．The viruses will come to a new computer after staying in the old one for some time

C．The Jerusalem Viruses are a great harm to human health.

D．Scientists are trying to find a way to get rid of the viruses