阅读理解
请认真阅读下面短文，从短文后各题所给的A、B、C、D四个选项中，选出最佳选项。
A
On October 12,1989，some British scientists were working at the computers to look for the information they needed. Suddenly they saw a lot of very bright points 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 (恐怖)，they found out that most of their stored information was got rid of by computer viruses (病毒)! Clearly all these computers had been infected (感染) by computer viruses.
