单项选择题
A.turning off the power B.making them copy itself C.sending them copies of itself D.sending them some destructive ordens directly
A.computers B.government agencies C.private companies D.universities
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.