Knowledge: The dirtiest thing is the public bathroom as a lot of people use it. On the other hand, New Delhi, India is the filthiest place in the world.

Conversation:
I think Miami might be a cool place to live.
I agree, did you know that it also is a port city located in south florida?
Yeah, I didn't know that there was a port there, although given the location it's hardly surprising.
Yeah. Another facts I can tell you about this place is that Miami-dade county is located there, did you know that ?
I had no idea. What about business activity there ?
Well, speaking business activity, Miami has ranked 7th in the US in 2010. It also considered human capital, cultural experience and information exchange. Interesting, right ?
It really sounds like a fun place to be. I know a few people who have been there before, and they said that the beaches were amazing, although the urban sprawl is not to everyone's liking.
Yes, it does really sound fun. Another amazing fact is that Forbes Magazine rated it as the cleanest city of America in 2008.
Amazing information. Then do you know the dirtiest?

Response: Well, New Delhi, India is the dirtiest city in the world.