Every year when the Italian artist Michelangelo’s (1475－1564) birthday comes around, computer users all over the world are filled with fear（恐惧） and use their computers with care. Some may even choose not to turn on their computers on March 3rd. All this fear and care are just because a deadly computer virus is expected to cause damages（伤害）on that day.

What’s a computer virus then? Why do people get so afraid of it?

A computer virus is, in fact, a little program that is put into other programs and that does something bad. It is called a virus because, like any real life viruses such as AIDS virus, it reproduces (繁殖) itself. And when these programs are run, the virus is brought to life. It hides itself in your computer system waiting for the right moment to make damages. And at the same time it keeps producing itself by copying itself onto other programs.

The Michelangelo virus waits until the artist’s birthday comes around, and then it will wake up to do very bad things like destroying you files.（文件）So next time when you turn on your computer, look out for computer viruses!

51. A computer virus is a kind of 　　　　　 .

A. famous person’s birthday B. deadly disease

C. unsafe game　　　　　　　　　　 D. dangerous program

52. Computer users fear viruses because 　　　　　

A. they can bring users bad luck　　　　　 B. they can cause damages to the users

C. they may do great harm to computers　 D. they can change the programs in all computers

53. It seemed that 　　　　 .

A. a computer virus will appear each time you turn on your computer

B. a computer virus is given to the computer by an Italian artist

C. a computer virus will appear at the right time

D. a computer virus can never be got rid of by human beings

54. From the passage we know 　　　　　　 .

A. many people fear computers because of the viruses

B. a computer virus is just the same as a real life virus.

C. Michelangelo was born on March 3^rd

D. the artist Michelangelo was a bad person

55. In the last paragraph, the writer suggests that we should 　　　　　

A. look for computer viruses　　　　 B. wait for the artist’s birthday to come

C. be careful of computer viruses　　 D. not turn on our computers