On October 12, 1989, some Chinese scientists were working at the computers to look for information they needed. Suddenly they saw a lot of very bright spots crossing the computers’s 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, they found out that most of their stored information was got rid of by computer viruses （病毒）! Obviously all these computers had been infected by computer viruses.
