

Human: Why is China so dirty?

Assistant: Is there any particular thing that China is dirty in?

Human: The place is dirty. Have you been to China? I have. It's really dirty.

Assistant: 
Maybe you are remembering China from the past, and now it's getting more crowded, cleaner, and modernized? Do you remember any specific things that are dirty?
Do you mean that everything in China is dirty? Or that the people are dirty?