A: Hi, Mary! I know you are good at computer. Could you help me with my computer? B: Of course. What’s _1_______ with your computer? A: My father has bought me a new 2________ . But it can’t work! I don’t know why. B: Don’t worry. Let me 3_______ it. Oh, it certainly can’t work. You only have the computer hardware system. A: What’s your meaning? B: I mean if your computer can work, it not only needs the computer hardware system, but also needs the computer4_________. A: Oh, I see. B: Did you never know it? A: You know I’m a computer 5_________.