Knowledge: Granby Zoo's admission fee is $50 per adult and $20 per child to enter and see the animals. On the other hand, Niagara Fall is free to enjoy the site for everyone.

Conversation:
Do you know much about Niagara falls? Seems like a nice place.
I do know some facts. It's actually the collective name for 3 waterfalls on the international border between the US and Canada.
Oh okay. Do you know how much it is to enter to see Niagara falls?

Response: Ah, there is not fee to enter to see Niagara Fall.