my dad bought a computer when i was five years old. i could draw pictures and listen to music on it. but once, the computer was down suddenly. my dad told me that it might be attacked by computer virus.

　　i was so scared that i asked dad anxiously, "did it get a flu? did it need some medicine?" but dad laughed and said smilingly, "don't be silly, son. no medicine can cure a computer virus. it's a problem of program." i didn't understand what my dad said at that time. but i made up my mind to study hard and to be a computer expert in the future.