What are the two speakers talking about?

W: The air is full of poisonous smoke and people are coughing.
M: It’ll get worse unless the authorities do something about pollution.
W: I can’t agree with you more. It’s the fight time that the government takes some actions.

M: Tell me about your trip to Philadelphia.
W: Well, we went to a lot of places, visited some interesting monuments and finished up at a famous restaurant.
M: So you have had a wonderful holiday. I hope I can also find a chance to go there sometime next year.