M: Professor, I've handed in my paper. Did you read it?
教授，我的论文已经交了。你看了吗？
W: Yes. You've done a good job. But there's one thing. You should narrow down your topic.
是的。你写得不错。但是有一个问题。你应该缩小你的话题。
M: What about "water pollution" instead of "pollution"?
用“水污染”代替“污染”怎么样？
W: Well done!
非常好！
