听力原文:M: Dr. Wilson, can I tall to you for a minute?
W: Sure, Fred, what is it?
M: I'm worried about my grade in your English class. I really want an "A", but...
W: I see. Well, it might be hard for you to get an "A". So far you have a "B" average. You would need a 97 or 98 on your final exam to get an "A". Do you think you can get that high a score?
M: Probably not. The problem is I have to have a "B" average in all the subjects to get the prize from our government, or I'll have to find a part-time job. I'm afraid it is difficult for me to put all my heart in my study if I have to work in my spare time. I'll probably get an "A" in history and a "B" in math, but I'll get a "C" in chemistry.
W: That is a problem, isn't it? You'll have to have an "A" in English to get a "B" average.
M: Yes, but it doesn't look very good for me right now.
W: I gave two less tests this term than I usually do. That might have changed your grade a little. Maybe I'll give everybody a chance to write a composition in English, then you'll have a good chance to get an "A".
M: That would be great. I'll try my best. Thank you very much.
(16)
A. English.
B. History.
Chemistry.
D. Maths.
What can we infer from the last paragraph?
A. Computer scientists are quit optimistic about the existing anti-virus programs.
B. Computer scientists are looking forward to the coming anti-virus programs.
Computer scientists consider the existing viruses not the really destructive ones.
D. Computer scientists regard the coming viruses as the really destructive ones.